There is no facility to actually record the miles entered, travelling to and from a property, and then having expenses calculated automatically on the back of this.
Instead, mileage expenses are entered under: Property Manager ==> Expenses.
You simply enter what you are claiming and assign it to the category 'Travel'. You can enter the amount of miles traveled for each expense claim in the 'Description'.
This will then be automatically claimed as deductible expense on the landlord tax report.