The Payment option is available at the bottom of the Order screen in POS. It provides various methods to pay the bill. Once Payment is selected:
The Payments window appears where you can view the following:
The Balance Due:
The available Payment Methods, each represented by a button.
Description containing each Method, Status and Amount paid in payment screen.

Select a Payment Method, enter the Amount then click Submit to close the payment.
Once a Payment has been completed, the Receipt will be moved to Closed status.