https://github.com/zkp2p/zk-p2p/tree/develop/circuits-circom

here's more generic email related project that may work with any payment provider sending notifications via email.

https://github.com/zkemail/zk-email-verify

bitcoin

The Taboo Against P2P Liquidity Providers Must End

siggy47

Here's project that leverages Venmo 
https://github.com/zkp2p/zk-p2p/tree/develop/circuits-circom
here's more generic email related project that may work with any payment provider sending notifications via email.
https://github.com/zkemail/zk-email-verify