There are a few methods to pay an invoice in your KnownHost Client Portal. This article will cover the most direct way to process the invoice.
If there is an unpaid invoice on your account, when you log in you'll see a dialog box similar to the one shown in this screenshot.
The most direct way to pay/settle the invoice is demonstrated here:
The payment will NOT be processed if you do not press the final "SUBMIT PAYMENT" button.