Greetings, @johnyule1-hotmai,
You've reached the right support to help you with your expenses.
If you are manually entering expenses and categorising them to car/vehicle expense, rather than using the mileage tracker, the system will tag it as dis-allowable.
Only Travel expenses in that case will be allowable. To update it, you must change the category of the transaction.
For the list allowable expenses, please see this link here: Self-employed business expenses: all you need to know.
Additionally, the following article also explains about car, van, and travel expenses.
If you need anything else, please let me know in the comment below. I'll be right here if you need further assistance with QuickBooks Self-Employed.