Used someone else's car for a few weeks- for work only. Stride App kept track of miles for work. how do i do that? THX

You will enter this as a vehicle expense in TurboTax.  When asked if you own the vehicle, select This vehicle isn't mine.  You can then enter the actual expenses you incurred while using the vehicle. 

You cannot take the standard mileage deduction on a vehicle you were just using that you did not own.