How do I apply a payment?
You can apply a payment to a single order at a time or utilize a split payment from the account screen.
Order: Look for the payment button in the row of buttons at the top to open up the payment window. You can also access this screen during the completion wizard.
Account: You can also the $Payment button from the Overview and Details tab and look for the "new payment" button. From here, enter in the payment information and then select which orders you wish to apply that payment to by clicking the checkbox next to them.