If there is an open credit memo for the customer you are creating an invoice for,

There will be a pop-up message.

If you are ready to process the payment and apply the credit memo,

Click “YES” to view and apply the credit memo. If you are just creating an invoice and will be processing the payment later, click “NO”.

(Screenshot below is when you click “Yes”, this “credit memo check” will pop-up)

Click “APPLY” and there will be a pop-up.

Check the box under “available credits” and click “SAVE”

Find “Receive Payment” under “Customer”

Then click on “Create Payment” located on the top right side of the page

Find the customer

Once you select the customer, open invoice(s) for the customer will generate on the bottom side under the customer information

On the right side of the invoice, there will be an option for “credit” under “apply”

Click on “credit” and there will be a pop-up with all the available credits

Check the box next to the credit you want to apply then “SAVE”