Some challenges have failed

[PaoPaoPao]

The OS is Ubuntu 22.04.

I entered the following command, but I am having trouble with an error. Could you please help me?

sudo apt update
sudo apt install certbot python3-certbot-nginx nginx
sudo systemctl start nginx
sudo systemctl enable nginx
sudo vim /etc/nginx/sites-available/default

I typed the following in Vim
server_name sample.com;

Reloaded Nginx and typed the following command
sudo systemctl reload nginx
sudo certbot --nginx -d sample.com

The following error occurred
Hint: The Certificate Authority failed to verify the temporary nginx configuration changes made by Certbot. Ensure the listed domains point to this nginx server and that it is accessible from the internet.

Some challenges have failed.
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot

[9peppe]

Do you own that domain? Does it point to your server?

Please only use example.com, example.net, example.org, *.example if you need example domains.

[MikeMcQ]

@PaoPaoPao

I typed the following in Vim
server_name sample.com;

To use the --nginx plugin you should have a full server block for HTTP (port 80) in nginx. That one line is not enough.

Something like this is the minimum.

server {
    listen 80;
    listen [::]:80;     # if using IPv6
    server_name example.com www.example.com;
    root /var/www/html;       # as appropriate for your system
}

[PaoPaoPao]

Dear 9peppe san,
Thank you for your message.

Domain is sample not my orijinal domain...
After get SSL Certificate , i will type https://sample.com on browser

Server is X server VPS

[PaoPaoPao]

Dear MikeMcQ san,
Thank for your very kindly message!

sudo certbot --nginx -d sample.net -d www.sample.net

But result is fail.

Port 22 and 80 is opened.
Firewall is opend.
sample.com's DNS is no problem..

Now i don't know wha is root cause of this problem

I will contnue investigate about this problem

[MikeMcQ]

@PaoPaoPao

But result is fail.

What was the exact error?

It would be easier to help you with your actual domain name

Does the test from this website succeed?

https://letsdebug.net

[PaoPaoPao]

After turning off the packet filter settings, the SSL certificate was issued.

Need i re-setting packet filter settings turn on ?