You need to add a NIP-57 (Zap) supported wallet into your Nostr profile.

5 wallets I'm aware of with NIP-57 support are

Strike

Bitcoin Jungle

stacker. news

vida.page

ln tip bot

Can't, you don't have your LN address setup in your Nostr bio.

Some of y'all are missing out on some free sats from me by not having your LN Address entered into your Nostr Bios.

I've been firing off 100 sats to most of my new follows as well as random notes that I like.