As you have not been in the US for 5 years or part years on a F1 visa, you are still a nonresident for 2018.

TurboTax does not support nonresident returns.

However we have a partnership with Sprintax offering a nonresident tax filing solution to our TurboTax customers.

Visit the TurboTax/Sprintax site for more info or to get started.