It is explained here: https://github.com/Cameri/nostream#configuration
there is a `.nostr` directory containing a `settings.json`, it's in there. here's what it looks like from the repo:
https://github.com/Cameri/nostream/blob/main/.nostr.local/settings.json
only the one in your deployed relay won't have the trailing `.local` on it
It is explained here: https://github.com/Cameri/nostream#configuration
