VAT Registration for Exception

Hi, I need to register for VAT as I will be going over the threshold, but this will be temporary so I also need to request an exception. I'm having issues with just the first step - registering for VAT. After I log into my business tax account, I go to add VAT, then get a message saying I can only do this from a business tax account...which I am already logged into. Is this a bug, or something that I am doing wrong?

Hi Catherine,
Please follow the steps from this link:
Register for VAT
If you have any difficulties please contact our Helpline as below:
VAT: general enquiries.
Thank you.