If you would like your customers to have a printed receipt with a signature, tip and total line included, you will need to enable "2 Step Pay".
To do this, tap the gear icon, then settings, and set "2 Step Pay" to yes.
Once 2 Step Pay is enabled, you can enter your orders as normal.
On the payment screen, you will swipe the credit card as normal.
Once swiped, a receipt will print and the screen will change to indicate a capture or reprint of the receipt.
After the customer has signed, tap the "Capture" button. You will then need to enter the total amount from the receipt. This should include the sales total and tip both.
Once you tap "Finish" your payment will be indicated at the top of the window. Tips will automatically be calculated.
A card that has been pre-authorized, is also visible and marked with a BLUE "Authorized" in the receipt history. You may open or capture the order from this screen as well.