If the list of items entered into the ordering screen is complete and the customer is ready to pay and leave with the goods, just select Cash or Card as the payment type.
If you select Cash the Tendered box is highlighted in yellow so you can enter the amount of cash tendered. When you push the Enter key the amount of change due to the customer appears in the change box and the Print button is highlighted in green. If you select Card, then just the Print button is highlighted in green.

Once you have obtained the change or processed the card payment just push the Print button and the receipt is printed on your designated receipt printer.
The Order screen is cleared ready for the next order.