Well, it is too late to file for a refund now for any year earlier than 2017, and the 2017 Statute of Limitations for refunds is about to expire as well. In addition, TT currently only has software for 2017-2020. If this person owes taxes, though, he should see a local professional about catching up.
TurboTax software can only be used for tax years as far back as 2017---and even 2017 will soon be "retired" from availability. Tax refunds for years earlier than 2017 have been forfeited, but if tax is owed it still needs to be paid. The "someone" who has not filed tax returns should seek local paid tax help to get this sorted out. If he has not filed in years and owes tax, a tax pro may be able to negotiate with the IRS.
If your friend (??) has not filed in a long time, urge him to get it taken care of. His future Social Security benefits and/or Medicare may also be at stake.
What if I do not file my tax return?
If you want to use software to tackle this:
PAST YEAR RETURNS
Each tax year has to be filed separately using the forms for the specific tax year. They cannot be combined in any way--do not even put them in the same envelope when you mail them. Software for past years is available back to 2017. Any earlier years can only be prepared on paper forms by hand--and those refunds have been forfeited now.
The current online program can only be used for a 2020 return--no other year. And if you did not file a 2019 return you will have trouble e-filing 2020. When it asks for your 2019 AGI try using zero. If zero does not work then you have to print, sign and mail 2020.
Online preparation and e-filing for 2017, 2018 and 2019 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2017, 2018, or 2019 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Federal and state returns must be in separate envelopes and they are mailed to different addresses. Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.
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.
Earlier years can be prepared using paper forms and they can be mailed in. Prior year forms are available from the IRS.