Account credit is created when you make deposits to your customer account above the Cashbox or by standing order stating your customer number.
Please note that account credits are not always automatically posted.
If you receive notification of an open invoice, you must log into the Customer Center at: https://login.streampanel.net/ log in and, if necessary, allocate the credit to the corresponding invoice first.
Read here how to pay a bill: https://www.streampanel.net/kb/bezahlen-einer-rechnung/
Once there, you add existing credit to the invoice as shown in the screenshot below. The invoice is then paid and the corresponding products are automatically extended by the system.