That seems to be for dns resolving, not for ddns? Or am I missing something?

Most registrars also run DNS servers as part of the fee you pay for the domain. Usually they have an API. You can just use that to implement Dynamic DNS, there are even often tools for it. Do a search for your DNS registrar and dyndns.

Afraid.org is better than DuckDNS. (DuckDNS is not reliable and have been slow or down a lot.)

But it is still American.