If you are asking about filing your 2019 return, you will be able to e-file it up until October 15, 2020. After that e-fling will close and a 2019 return will have to be printed, signed and mailed. Any returns for tax years earlier than 2019 must be printed, signed and mailed--they cannot be e-filed.
If you are getting a refund, there is not a penalty for filing past the deadline. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
If you need to prepare a return for a tax year earlier than 2019 you have to purchase and download the desktop software to a full PC or Mac. The online program is ONLY for 2019--no other year.
https://ttlc.intuit.com/questions/1900990-how-do-i-file-a-prior-year-tax-return
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
