If your payment has been successful, you will receive a booking confirmation email with your parking pass attached and the vehicle registration which is authorised to park within the car park (Please check that these details are correct).
If this email has not been received. Then this would suggest that the payment has failed or not been completed. It is the motorists responsibility to ensue that payment has been made. You can also check in your account under My activity and then Active to see if your booking is live.
Making a purchase - Video