Can you recommend me a free domain registrar?

I want to try out some things with a secondary domain. I'd prefer ethical and non-shady providers. I have a fixed IP and a VPS to go with it, so it's really only about the domain. A subdomain is not enough. Even paying very little is not an option right now.

I just spent 15min searching the fediverse for this and the most relevant post is 3 years old. I know I can search the WWW and get lots of results, but I want your opinion!

TIA

edit: Not a .tld, not a subdomain. just a domain a lá example.com. Can be utterly random.