Hi, Justin_Joung
Thanks for your post.
Generally, the memo section in the pay slip is pulled from the employee's card, Payroll Details > Standard Pay section. If this memo does need to be changed on a per-transaction basis you would be looking at updating the transaction on the Pay Employee window prior to recording the transaction. This is similar behaviour to other parts of the product that will have a set default memo, which is based on default values.
Please let us know if you require any further assistance with this. We are happy to assist.
Best regards,
Doreen