here is what it says after apachectl -s
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 192.168.10.16. Set the 'ServerName' directive globally to suppress this message
VirtualHost configuration:
*:443 adventist-pic.org (/etc/apache2/sites-enabled/auppic-le-ssl.conf:2)
*:80 adventist-pic.org (/etc/apache2/sites-enabled/auppic.conf:1)
ServerRoot: "/etc/apache2"
Main DocumentRoot: "/var/www/html"
Main ErrorLog: "/var/log/apache2/error.log"
Mutex default: dir="/var/run/apache2/" mechanism=default
Mutex mpm-accept: using_defaults
Mutex watchdog-callback: using_defaults
Mutex rewrite-map: using_defaults
Mutex ssl-stapling-refresh: using_defaults
Mutex ssl-stapling: using_defaults
Mutex ssl-cache: using_defaults
PidFile: "/var/run/apache2/apache2.pid"
Define: DUMP_VHOSTS
Define: DUMP_RUN_CFG
User: name="www-data" id=33
Group: name="www-data" id=33
i am new at this can you help me out on what to do on this matter?
If that works, then re-running certbot --apache should offer you both names (adventist-pic.org and www.adventist-pic.org), and you can choose both of them to get a single certificate covering both.