You need to confirm each month that you’re still using that url if you’re in free tier. Otherwise it won’t be registered to you

I used duckdns for my jellyfin server, but after a week or so I started getting malicious site warnings from Firefox, and had to ‘accept the risk and continue’ every time. Ended up going back to noip. It’s a pain to renew every month, but I haven’t had any other problems with it.

I have a jellyfin server on a pi4. I recently bought a dell micro pc, but haven’t had the motivation to move the jellyfin server over to it yet.