Migrated from RPI to ODROID and lost DuckDNS access

Somehow, letsencrypt + duckdns entry to my home-assistant has been lost.
At the letsencrypt web site, I did not see they support duckdns anymore.
Is the combination of letsencrypt & duckdns still viable? Is my problem moving from PI to ODROID N2+ ? So does an ODROID environment eliminate this combo? BTW, the Nabu Casa entry works great.
I will be glad to provide more info ask requested (what would help?)
Error message file is available, but how do you attach a file here? Sorry, I am not forum methods knowledgeable. Thank you for any advise, Doug