It is possible to add credits on members for payable events
You need to do this immediately after you have created the event.
To add the credit on a member you need to follow these steps:
In a computer:
1. When you have created a payable event you need to click the event and go to payments
2. Click on payment and find the person that is supposed to get the credit balance
3. When the invoice opens you click the three dots and click ,,add transaction''. Then you put in the amount that they have remaining to the ,,invoice remaining amount'' lot.