If you use primal, go to edit your profile, it is the last two fields I was talking about.
Start with the last one, get yourself a NIP-05 aka Nostr address.
I just realised that the one I used requires talking directly to the operator nostr:nprofile1qqsdm7asdfezu5vn8nfhunkdkv93se8jvtumkk7kctv4e0h0cu50p9sprfmhxue69uhkummnw3ezu6rpdej8j6n4de4hjtnrdakszenhwden5te0ve5kcar9wghxummnw3ezuamfdejj7mnsw43rzcmvdvm8vcee0p5x5upcwy6kxamnxgmryam4vcex26p50f6hvam4wpn8gvpndpungar5w9ckumfhv5cx5un3xd6hqats8ylkyun0v9jxxctnws7hgun4v5q3kamnwvaz7tmjv4kxz7fwdehhxarjvaexzurg9ehx2ap0nl6gw6, if you don't want that, I can see that you can buy one at https://my.nostr.com/ too.