Correct -- If you received a 1099-NEC (nonemployee compensation) you would be considered an independent contractor running your own business. You would then be able to take either mileage or actual expenses for your automobile, along with any other business expenses. You would also be responsible for your own payroll taxes (Social Security, Medicare).
You could also talk with your employer and negotiate a reimbursement of the mileage or expenses you incur.
