There is no mandated billing method, but the ability to pay without registering an account is mandated. Additionally every charger has a unique id with a QR cod

There is no mandated billing method, but the ability to pay without registering an account is mandated. Additionally every charger has a unique id with a QR code. Usually you either just plug it in (first party charger) or just scan the QR code with your favorite charging app which will handles the billing (third party charger).