Which one do you need?
It depends almost entirely on your age and on whether you already hold a licence. Under 24 and starting out, the route is a CBT, then the theory test, then Module 1 and Module 2 on a bike in the category your age allows. At 24 or over, Direct Access goes straight to an unrestricted licence and there is no reason to take a smaller category first.
Every route starts with a CBT. There is no category you can test for without one.