Everyone should ask providers of paid relays they use to allow anyone to publish receipts when the zap request came from a pubkey with write permissions. I just did this for our own relay the other day:
Discussion
#[4] Does the filter do this?
Filter sits in front of our public relay aggregator so as long as the zap ends up on one of the many public relays we read from, it will make it to filter.
Only paid users can write to filter and we broadcast those notes back out.
We COULD add this to nostr.wine since it works like most paid relays, but it does open up a way to get spammed. We whitelisted most of the large wallet providers a while back but if you run your own zapper you’ll need to buy access for it as well.