Prego

Nip-57 is what allows the client (Amethyst in this case) to know that a lightning invoice was paid. And it needs to know in order to display it.

So both the lightning wallet (Alby) and the client (Amethyst) need to implement Nip-57 for it to work

https://github.com/nostr-protocol/nips/blob/master/57.md