Letsencrypt addon without port 80

I am using letsencrypt addon for receive SSL certificates for my doman like mydomain.com.

  1. My domain name provider is goddady.com and already made forwarding port 80 to my windows server. So when setup letsencrypt addon i see that in log
[16:21:49] INFO: Selected http verification
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer None
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for *******.com
Waiting for verification...
Challenge failed for domain *******.com
http-01 challenge for *******.com
Cleaning up challenges
Some challenges have failed.
 - The following errors were reported by the server:
   Domain: *******.com
   Type:   unauthorized
   Detail: Invalid response from

So like I understand I have to forward internet port 80 to the raspberry pi with hassio, but that port already goes to windows server with IIS. Can letsencrypt use for validation some other custom port like 3000?

  1. Everybody using DuckDNS but I don’t find the way how setup domain (mydomain.com) which not belong to *.duckdns.org domain. Is it possible?

Can’t use a custom port.

It does have DNS based validation, if you were using a suitable DNS provider. But I don’t believe godaddy is one of them. You’d have to do DNS hosting elsewhere