Hello Kayleigh3, Welcome to the Community, if you are claiming for fuel using the actual expenses method you can manually add an expense for the fuel costs using the car/van expenses as the category by adding the transaction manually in the banking section or import the banking transactions and add it, if you are using the QuickBooks Self Employed product or you can create your own expense category and expense or import the bank transaction and add it if you are using the QuickBooks Online product. More information can be found on that here under the 2nd option on this help article for Self Employed

We've added a link to the HMRC page as well in case that is helpful to you.

Any questions feel free to add them onto this thread and we'd be happy to go into more detail if needed.