Hi
I successfully generate the ssl certificate when i access my domain from browser it gave me error as mention below.
im not a developer so i have no idea about this error maybe this is common kindly advice necessary
1- NET::ERR_CERT_AUTHORITY_INVALID. ( error from Google Chrome)
thie is the result for domain scan
No NOT TRUSTED (Why?)
Mozilla Apple Android Java Windows
hello breaden
yes i did try using certbot but not for site
basically i have generate the security certificate for my vpn server and it worked perfectly but in the same machine i have a web server as well i jus need to install ssl certificate for my web server without interrupting my running vpn server .
when i run this command
certbot certonly --webroot -w /var/www/html/aj-group.ddns.net/ -d aj-group.ddns.net -d www.aj-group.ddns.net
It gave me this error
Challenge failed for domain www.aj-group.ddns.net
http-01 challenge for www.aj-group.ddns.net
Cleaning up challenges
Some challenges have failed.
IMPORTANT NOTES:
The following errors were reported by the server:
Domain: www.aj-group.ddns.net
Type: dns
Detail: DNS problem: NXDOMAIN looking up A for
www.aj-group.ddns.net - check that a DNS record exists for this
domain
Welcome to the Let's Encrypt Community, Braeden 
You have no A (or CNAME) record in your DNS for www.aj-group.ddns.net. Thus, attempting to fulfill an http-01 challenge for it, like you are trying to do, will fail.
Either add a CNAME record for www.aj-group.ddns.net pointing to aj-group.ddns.net or add an A record for www pointing to 2.90.212.139.
Once that's fixed, run this to test:
certbot certonly --webroot -w /var/www/html/aj-group.ddns.net/ -d "aj-group.ddns.net,www.aj-group.ddns.net" --dry-run
If that works, run this:
certbot certonly --webroot -w /var/www/html/aj-group.ddns.net/ -d "aj-group.ddns.net,www.aj-group.ddns.net" --keep
Thank You griffin
as i mention above im not a developer this is my first time to generate ssl certificate for website
it will be much appreciated if you can guide me or share some useful link
I gave you exact instructions on what to fix and how to fix it. 
You should be able to make the DNS changes through your account with ddns.net.
thank you griffin
i got it 
Keep in mind that the csrtbot commands I gave you will only acquire the certificate. It still needs be to properly installed to work.
Also, your port 80 in apache is configured for SSL, which won't work. Port 80 should be HTTP (without SSL) and port 443 should be HTTPS (with SSL).
This isn't good:
http://aj-group.ddns.net
400 Bad Request
https://aj-group.ddns.net
403 Forbidden
What's the output of this:
apachectl -S
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using aj-group.ddns.net. Set the 'ServerName' directive globally to suppress this message
VirtualHost configuration:
*:443 aj-group.ddns.net (/etc/httpd/conf.d/ssl.conf:40)
ServerRoot: "/etc/httpd"
Main DocumentRoot: "/var/www/html"
Main ErrorLog: "/etc/httpd/logs/error_log"
Mutex authn-socache: using_defaults
Mutex ssl-cache: using_defaults
Mutex default: dir="/etc/httpd/run/" mechanism=default
Mutex cache-socache: using_defaults
Mutex authdigest-opaque: using_defaults
Mutex watchdog-callback: using_defaults
Mutex proxy-balancer-shm: using_defaults
Mutex rewrite-map: using_defaults
Mutex ssl-stapling-refresh: using_defaults
Mutex authdigest-client: using_defaults
Mutex lua-ivm-shm: using_defaults
Mutex ssl-stapling: using_defaults
Mutex proxy: using_defaults
PidFile: "/etc/httpd/run/httpd.pid"
Define: DUMP_VHOSTS
Define: DUMP_RUN_CFG
User: name="apache" id=48
Group: name="apache" id=48
What are the outputs of these:
sudo ls -la /etc/apache2/sites-available
sudo ls -la /etc/apache2/sites-enabled
What are the contents of this file:
/etc/httpd/conf.d/ssl.conf
ls: cannot access '/etc/apache2/sites-available': No such file or directory
[root@aj-group ~]# cat /etc/httpd/conf.d/ssl.conf
#
# When we also provide SSL we have to listen to the
# standard HTTPS port in addition.
#
Listen 443 https
##
## SSL Global Context
##
## All SSL configuration in this context applies both to
## the main server and all SSL-enabled virtual hosts.
##
# Pass Phrase Dialog:
# Configure the pass phrase gathering process.
# The filtering dialog program (`builtin' is a internal
# terminal dialog) has to provide the pass phrase on stdout.
SSLPassPhraseDialog exec:/usr/libexec/httpd-ssl-pass-dialog
# Inter-Process Session Cache:
# Configure the SSL Session Cache: First the mechanism
# to use and second the expiring timeout (in seconds).
SSLSessionCache shmcb:/run/httpd/sslcache(512000)
SSLSessionCacheTimeout 300
#
# Use "SSLCryptoDevice" to enable any supported hardware
# accelerators. Use "openssl engine -v" to list supported
# engine names. NOTE: If you enable an accelerator and the
# server does not start, consult the error logs and ensure
# your accelerator is functioning properly.
#
SSLCryptoDevice builtin
#SSLCryptoDevice ubsec
##
## SSL Virtual Host Context
##
<VirtualHost _default_:443>
# General setup for the virtual host, inherited from global configuration
#DocumentRoot "/var/www/html"
#ServerName www.example.com:443
# Use separate log files for the SSL virtual host; note that LogLevel
# is not inherited from httpd.conf.
ErrorLog logs/ssl_error_log
TransferLog logs/ssl_access_log
LogLevel warn
# SSL Engine Switch:
# Enable/Disable SSL for this virtual host.
SSLEngine on
# List the protocol versions which clients are allowed to connect with.
# The OpenSSL system profile is used by default. See
# update-crypto-policies(8) for more details.
#SSLProtocol all -SSLv3
#SSLProxyProtocol all -SSLv3
# User agents such as web browsers are not configured for the user's
# own preference of either security or performance, therefore this
# must be the prerogative of the web server administrator who manages
# cpu load versus confidentiality, so enforce the server's cipher order.
SSLHonorCipherOrder on
# SSL Cipher Suite:
# List the ciphers that the client is permitted to negotiate.
# See the mod_ssl documentation for a complete list.
# The OpenSSL system profile is configured by default. See
# update-crypto-policies(8) for more details.
SSLCipherSuite PROFILE=SYSTEM
SSLProxyCipherSuite PROFILE=SYSTEM
# Point SSLCertificateFile at a PEM encoded certificate. If
# the certificate is encrypted, then you will be prompted for a
# pass phrase. Note that restarting httpd will prompt again. Keep
# in mind that if you have both an RSA and a DSA certificate you
# can configure both in parallel (to also allow the use of DSA
# ciphers, etc.)
# Some ECC cipher suites (http://www.ietf.org/rfc/rfc4492.txt)
# require an ECC certificate which can also be configured in
# parallel.
SSLCertificateFile /etc/pki/tls/certs/localhost.crt
# Server Private Key:
# If the key is not combined with the certificate, use this
# directive to point at the key file. Keep in mind that if
# you've both a RSA and a DSA private key you can configure
# both in parallel (to also allow the use of DSA ciphers, etc.)
# ECC keys, when in use, can also be configured in parallel
SSLCertificateKeyFile /etc/pki/tls/private/localhost.key
# Server Certificate Chain:
# Point SSLCertificateChainFile at a file containing the
# concatenation of PEM encoded CA certificates which form the
# certificate chain for the server certificate. Alternatively
# the referenced file can be the same as SSLCertificateFile
# when the CA certificates are directly appended to the server
# certificate for convenience.
#SSLCertificateChainFile /etc/pki/tls/certs/server-chain.crt
# Certificate Authority (CA):
# Set the CA certificate verification path where to find CA
# certificates for client authentication or alternatively one
# huge file containing all of them (file must be PEM encoded)
#SSLCACertificateFile /etc/pki/tls/certs/ca-bundle.crt
# Client Authentication (Type):
# Client certificate verification type and depth. Types are
# none, optional, require and optional_no_ca. Depth is a
# number which specifies how deeply to verify the certificate
# issuer chain before deciding the certificate is not valid.
#SSLVerifyClient require
#SSLVerifyDepth 10
# Access Control:
# With SSLRequire you can do per-directory access control based
# on arbitrary complex boolean expressions containing server
# variable checks and other lookup directives. The syntax is a
# mixture between C and Perl. See the mod_ssl documentation
# for more details.
#<Location />
#SSLRequire ( %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \
# and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \
# and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \
# and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \
# and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20 ) \
# or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/
#</Location>
# SSL Engine Options:
# Set various options for the SSL engine.
# o FakeBasicAuth:
# Translate the client X.509 into a Basic Authorisation. This means that
# the standard Auth/DBMAuth methods can be used for access control. The
# user name is the `one line' version of the client's X.509 certificate.
# Note that no password is obtained from the user. Every entry in the user
# file needs this password: `xxj31ZMTZzkVA'.
# o ExportCertData:
# This exports two additional environment variables: SSL_CLIENT_CERT and
# SSL_SERVER_CERT. These contain the PEM-encoded certificates of the
# server (always existing) and the client (only existing when client
# authentication is used). This can be used to import the certificates
# into CGI scripts.
# o StdEnvVars:
# This exports the standard SSL/TLS related `SSL_*' environment variables.
# Per default this exportation is switched off for performance reasons,
# because the extraction step is an expensive operation and is usually
# useless for serving static content. So one usually enables the
# exportation for CGI and SSI requests only.
# o StrictRequire:
# This denies access when "SSLRequireSSL" or "SSLRequire" applied even
# under a "Satisfy any" situation, i.e. when it applies access is denied
# and no other module can change it.
# o OptRenegotiate:
# This enables optimized SSL connection renegotiation handling when SSL
# directives are used in per-directory context.
#SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire
<FilesMatch "\.(cgi|shtml|phtml|php)$">
SSLOptions +StdEnvVars
</FilesMatch>
<Directory "/var/www/cgi-bin">
SSLOptions +StdEnvVars
</Directory>
# SSL Protocol Adjustments:
# The safe and default but still SSL/TLS standard compliant shutdown
# approach is that mod_ssl sends the close notify alert but doesn't wait for
# the close notify alert from client. When you need a different shutdown
# approach you can use one of the following variables:
# o ssl-unclean-shutdown:
# This forces an unclean shutdown when the connection is closed, i.e. no
# SSL close notify alert is sent or allowed to be received. This violates
# the SSL/TLS standard but is needed for some brain-dead browsers. Use
# this when you receive I/O errors because of the standard approach where
# mod_ssl sends the close notify alert.
# o ssl-accurate-shutdown:
# This forces an accurate shutdown when the connection is closed, i.e. a
# SSL close notify alert is sent and mod_ssl waits for the close notify
# alert of the client. This is 100% SSL/TLS standard compliant, but in
# practice often causes hanging connections with brain-dead browsers. Use
# this only for browsers where you know that their SSL implementation
# works correctly.
# Notice: Most problems of broken clients are also related to the HTTP
# keep-alive facility, so you usually additionally want to disable
# keep-alive for those clients, too. Use variable "nokeepalive" for this.
# Similarly, one has to force some clients to use HTTP/1.0 to workaround
# their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and
# "force-response-1.0" for this.
BrowserMatch "MSIE [2-5]" \
nokeepalive ssl-unclean-shutdown \
downgrade-1.0 force-response-1.0
# Per-Server Logging:
# The home of a custom SSL log file. Use this when you want a
# compact non-error SSL logfile on a virtual host basis.
CustomLog logs/ssl_request_log \
"%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
</VirtualHost>
SSLEngine on
SSLCertificateFile /etc/letsencrypt/live/aj-group.ddns.net/cert.pem
SSLCACertificateFile /etc/letsencrypt/live/aj-group.ddns.net/chain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/aj-group.ddns.net/privkey.pem
Can you please edit your last post and put 3 backticks (```) on a line before and after your output.
Much better! 
my apology 
What are the contents of this file:
/etc/httpd/httpd.conf
content for site is under
/var/www/html
I'm looking for the http configuration file (that isn't active).
Maybe this:
sudo ls -la /etc/httpd/conf.d