In order to use your credits, you must first fill in all the information required to take charge of your project. Once you have passed step "3 - Your information" you can choose which payment method you wish to use.
If the number of credits available is not sufficient, you can complete the payment with the bank card of your choice.
If you have credits in your personal account and it is not possible for you to use them at the time of payment, please make sure that you are not making a business booking.