With online payments integrated, you can charge guests' credit cards directly from the system and also make refunds for these transactions. 

To make a refund, open the reservation where the payment was taken, and navigate to the Payments tab.

There, directly in the payment table, you will find a button to make a refund of the selected transaction.

Click on the button and then confirm the refund amount and transaction in the Refund now window.

On Refund payment click, the system will make the refund to the guest's credit card and register the transaction on the payments list.