Publish a /.well-known/nostr.json in the domain you want with:
{
"names": {
"_": "
}
}
Then load http://nostr.rocks, hit Settings, and insert your domain in the NIP-05 Identifier field (e.g.: vitorpamplona.com)
Discussion
Example:
1. https://vitorpamplona.com/.well-known/nostr.json
2. 
Spec: https://github.com/nostr-protocol/nips/blob/master/05.md
tried this, doesn’t work for me