3DS (3D Secure) is the protocol that identifies each transaction with the card issuing bank. Once the identification process is complete, the two institutions (banks) have confirmed the safety of the transaction and proceed to complete the transfer.
When you make an online transaction with a payzy card, you will receive a push notification on the mobile device you use to access the Payzy app. Once you pass the relevant security check, you can either accept or reject the transaction. If you accept it, the transaction is executed normally and your card is charged with the amount you are required to pay to the merchant.
If you reject it, the transaction will not go through.