NIP-05 prove that you own a domain or are part of a group hosted on the domain, that's all.
Owning a domain is connected to a indentity, so you can prove it.
Join a "shared domain" is useful to prove you are not a bot, so you can be whitelisted by a relay that uses this anti-spam policy.
So it doesn't really 'prove' anything at all right, except that 'someone' with said name created a NIP-05 verification at that domain?
you need to have access to the domain, so you can enter data (a small json file).
OR you can register at a domain that does this for you. Like I did by registering at getalby.
Look at the video (Step by step guide video for #nostr starters)
Thanks! Not sure why but the vid link isn't live and can't be copied separately from the rest of your post. I can do it manually, just curious why the link isn't live?
