There could be a couple of reasons for this.
Please log into your account and complete the information requested. Once you have done this your account will be sent to your landlord for authorisation.
Sometimes, the time this approval takes can vary from landlord to landlord, depending on volume and their internal procedures. Please do not make payment whilst you are awaiting approval as it may not be possible to refund. You could also try contacting your landlord to request that they process this as soon as possible for you.