mileage tool

Hi can anybody help? I have rung support but they had no idea, other than to do a journal but didn't know how to

As a sole trader, on cash basis accounting, I record my mileage in a mileage book. Then I buy all my petrol from my personal account. I believe that I should be using a 'mileage tool' , then transfering the total weekly into my personal account.

But where is the mileage tool?? and how do I use it please? as obviously I don't want to put it as drawings.

Up to now I havent included mileage, except as a written deduction at the end of the year before submitting my return. I would prefer to do it properly though.

Also my deductions for share of mortgage heating etc? is there somewhere for theses?

Many thanks