You need a LN wallet that supports LNURL. And the. You enter the relevant email address into your NOSTR account. I had been using Muun and that doesn’t support LNURL. Lots of folk seem to be using Wallet of Satoshi but I’m surprised given it’s custodial and closed source…
I’m intending to get Phoenix as meant to be the best non custodial and supports LNURL. Just haven’t got round to it.