I'm also a little confused. Are they really just a Lightning payment to someone's LN-URL or Lightning Address? Or is there more to it? I asked some friendly stranger to send me a zap on nostr general to see what would happen and they just sent some sats to my lightning address, I think. BUT NIP-57 sounds like there is a special nostr message for zaps. So maybe I'm using the terminology wrong? If I request a zap, should I be using a nostr client that can post a NIP-57 compliant message that has an invoice or qr code with my LN-URL?