I have a couple questions... do I need to reply something in particular to the message? And should I follow that npub?
New features of http://magicwebstore.xyz:
- Store metadata: view any store's activity metrics
- Nostr auth: connect your store to your nostr identity
- Notifications: authed merchants get a DM when they get a sale
- Visa gift cards: turn your store proceeds into dollars
Try it out today! magicwebstore.xyz

Discussion
There are 4 steps to authenticating. Step 4 displays something called a "proof of ownership" which is some base64 encoded text. You're supposed to copy that and reply to the DM with it. I've clarified that in the instructions so hopefully no one else will be confused.