Thanks for joining this conversation, @CaseyHart.

Since the payment was already entered, you can locate and open it in the Customer Center in QuickBooks Desktop (QBDT). From there, you'll be able to send a receipt to the customer.

Here's how:

1. In QBDT, go to the Customers menu at the top to get to the Customer Center.
2. Select the customer's name in the left pane, then locate the payment (sales receipt) in the Transactions tab and open it. 
3. Click the Email option at the top, then pick Sales Receipt. 
4. Enter the customer's email address and hit OK to send.

Just in case, I'll add these articles for future reference:

• Create sales receipts.
• Process a credit card payment in QuickBooks Desktop.

Please leave a comment below if you have any other issues or concerns, and I'll get back to you right away. I'm always here to help. Have a great day!