Thank you. Very helpful. DuckDNS validation appears to have worked without port 80 being open. It appears that No-IP can be used as a DDNS, however, only using http validation, since it does not have the required API. Makes sense now.
I agree with the port 80 practice for a public webpage. Anyone probing ports will always try 80 and 443 anyway.
Is there an image to use in Docker to maintain the certificate, to isolate the validation information (like API credentials) from the SWAG container?
Thanks.