I hope you are having a great weekend so far! I'd be more then happy to assist with your question.
We will first want to locate our customers transaction list, and double click on the payment as shown down below:
Once we have located the payment and have the transaction open, we can select "More" and select void/delete:
If the payment is for a vendor/supplier, we will want to locate our vendor/suppliers transaction list as shown in the image below:
Then we will want to locate and double click the payment in the transaction list:
Then we can select "More" and choose void or delete as shown below:
I hope this helps! Let me know if you have any further questions, and have a safe Halloween!