First one is DOP. The Data Ownership Protocol (DOP) is utilizing zero-knowledge proofs in order to allow flexible transparency on top of Ethereum L1.
It's completely free to complete. All the steps take place on the SepoliaETH Testnet. Takes about 5min to complete
As always it's recommended to use a fresh wallet!
https://doptest.dop.org/id=5bnVpYR