remyers on Nostr: I took a quick look at and I think the payer's nostr app needs to pass to the payer's ...

I took a quick look at https://nostr.how/en/zaps and I think the payer's nostr app needs to pass to the payer's Lightning app via an API call:
- the static invoice of the note's poster
- an ID for the zap that the payer's LN app should include as a note with the payment
- the sats amount the payer selected

The zapper's nostr app can then post a note about the zap with the ID, amount and relays to respond to. This should be possible without nostr specific changes to Lightning clients.

The note lets the zap receiver know what note was zapped. I'm not sure how the zap receiver can confirm the zap though. They would need their Nostr app to query their Lightning app.. or maybe the other way around?
Then they can post the confirmation note to the relays specified by the sender.