Nostr-relay, Umbrel has a package (see attached screenshot, it shows how it's logging follows) but you can also install it anywhere as there a git
https://github.com/BlockChainCaffe/Nostr-Relay-Setup-Guide (nice guide)
https://github.com/scsibug/nostr-rs-relay (actual program)

https://image.nostr.build/42b0e5720da870904dbff04f3c9cc76fbb0c0402809cdfd017802b2f88281f1f.png