This one is quite easy to set up:

GitHub

GitHub - scsibug/nostr-rs-relay: Mirror of https://sr.ht/~gheartsfield/nostr-rs-relay/

Mirror of https://sr.ht/~gheartsfield/nostr-rs-relay/ - scsibug/nostr-rs-relay

You can even run it on your own raspberry pi if you get a static IP address from a VPN provider 😀

First you gotta ask what you want your relay to do and who you want to access it.