It depends. If you are a W-2 employee, the mileage is not deductible, because unreimbursed employee expenses are not allowed, through 2025 (see: Are Unreimbursed Employee Expenses Deductible?).
If you are self-employed, vehicle expenses are deductible. You can choose mileage or actual expenses. In order to claim vehicle expenses and mileage, you need to add a vehicle to your business; here are the steps in TurboTax Online:
- Navigate to Federal > Wages & Income > Self-employment income and expenses
- Edit your business
- Choose add expenses for this work
- Choose Vehicle and Continue
- Vehicle now appears in the list of expenses, choose the pencil icon to the right of vehicle expenses
- Answer the interview questions about the vehicle, and enter the related expenses
