After much troubleshooting I found out that my ISP is blocking port 80 (unless I pay extra for it). Then I learn that there are two alternative DNS-based authentication methods for Letsencrypt. I'm using DuckDNS and I see there is also a specific validation method for that too (VALIDATION=duckdns). However, that also gives me an error that I can't figure out (see below).
At this point, before I take on more trouble, I'm wondering what is the preferred method for me to obtain a cert. Also, is this utility at all relevant/helpful? https://hub.docker.com/r/linuxserver/duckdns/
I appreciate any help!
Error from Letsencrypt:
Waiting for verification...
Challenge failed for domain duckdns.org
dns-01 challenge for duckdns.org
Cleaning up challenges
Some challenges have failed.
- The following errors were reported by the server:
Detail: DNS problem: NXDOMAIN looking up TXT for
ERROR: Cert does not exist! Please see the validation error above. Make sure your DUCKDNSTOKEN is correct.