When the sales receipt prints from QuickBooks Point of Sale after a credit, there is no signature line (despite there being authorization numbers in the Notes field/the transaction being approved).
1. Open QuickBooks Point of Sale.
Open up QuickBooks Point of Sale, and sign in as a cashier with permissions to change Point of Sale settings (or the Sysadmin user).
2. Open the PT-Settings screen.
Click on the green I Want To... menu, and click on PT-Settings to open up the configuration screen for the Point of Sale integration.
3. Turn on signature line on receipt.
Click on the Receipt Options tab on the top, and check the Show signature on receipt box. Then, click Save.