There are no longer any services available for filing a 2018 tax return free of charge. To use TurboTax, you would have to buy, download and install the 2018 program on your computer to prepare the return: https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2018 tax return can no longer be efiled. It must be printed and mailed by you.
You could download the 2018 tax forms for free from the IRS and complete them by hand: https://www.irs.gov/forms-pubs/prior-year
