https://uselessshit.co/resources/nostr

Paid nip-05: https://nostrplebs.com/

Free nip-05: https://bitcoinnostr.com/

Basically you need to sign up with a nip-05 provider and then in your nostr client of choice post what they say… it looks like an emails

Could take a day to connect properly

The other option is to set out a nip-05 with your own domain… but I don’t know how to do that