Just a receipt. A receipt is not required for zaps.

Then it's not a Zap. We had Lightning payments in 2022 because Lightning addresses were on profiles. We didn't have Zaps, integration of Nostr into Lightning addresses, until approximately February 2023. This is like Stacker News and Orange Pill App saying Zaps for Lightning payment after @jb55 invented them because it's a cool and fun way to say it. It's an affinity scam.