It's because you don't have any relays as public inbox. Apps don't know where to send your zaps to. Please add 3 relays that you trust on the public outbox and public inbox section.
Nos.lol, nostr.mom are good ones.
Discussion
That should probably be done by default.
Too difficult to choose relays that will work for everyone. We set defaults for new users, but existing ones need to decide what they want to use.
Defaults also significantly centralize nostr.
