TurboTax Online/Mobile: Go to Schedule C. or go to the magnifying glass at top right of screen and search for Schedule C and select the Jump to link.
Answer Yes to Did you have any self-employment income or expenses? and answer the questions until you get the Select any expense categories or asset you have screen.
Select Assets: Choose "Assets" and then "Add an Asset."
Enter Details: Enter the details of the truck, including the purchase price, date of purchase, and business use percentage
Section 179 Deduction: You can elect to use Section 179 to deduct the entire cost of the truck in the first year