Cerbot failed using HA, DuckDNs and Let's

[Vicitocande]

I am using Let's encrypt in Home Assistant and I have an error when using it with my domain vicitocande.duckdns.org

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Requesting a certificate for vicitocande.duckdns.org
Certbot failed to authenticate some domains (authenticator: standalone). The Certificate Authority reported these problems:
Domain: vicitocande.duckdns.org
Type: connection
Detail: 83.55.31.67: Fetching http://vicitocande.duckdns.org/.well-known/acme-challenge/lt8VrfYFk1K7RCoWJ0Tq2Egm0SG7oxG1P5FcbklwI3o: Timeout during connect (likely firewall problem)
Hint: The Certificate Authority failed to download the challenge files from the temporary standalone webserver started by Certbot on port 80. Ensure that the listed domains point to this machine and that it can accept inbound connections from the internet.
Some challenges have failed.

Can you help me?

[Bruce5051]

Hello @Vicitocande, welcome to the Let's Encrypt community.

Using the online tool Let's Debug the results are an ERROR here https://letsdebug.net/vicitocande.duckdns.org/1312331

Best Practice - Keep Port 80 Open

Using nmap (from an IPv4 Address only) I find no ports opens.

$ nmap -Pn vicitocande.duckdns.org
Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower.
Starting Nmap 7.91 ( https://nmap.org ) at 2022-12-25 11:20 PST
Nmap scan report for vicitocande.duckdns.org (83.55.31.67)
Host is up.
rDNS record for 83.55.31.67: 67.red-83-55-31.dynamicip.rima-tde.net
All 1000 scanned ports on vicitocande.duckdns.org (83.55.31.67) are filtered

Nmap done: 1 IP address (1 host up) scanned in 203.57 seconds