Sorry---you cannot prepare a 2016 return using TurboTax. The current online program is only for 2021--no other year.
And...it is too late to get a refund for a 2016 return. That refund has been forfeited. But if you owe tax for 2016 the IRS still wants to be paid.
You can use the paper forms to prepare a 2016 return to mail in.
https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment
PRIOR YEAR FORMS FROM IRS
2016
Form 1040 https://www.irs.gov/pub/irs-prior/f1040--2016.pdf
Form 1040 Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2016.pdf
Form 1040A https://www.irs.gov/pub/irs-pdf/f1040a.pdf
Form 1040AInstructions https://www.irs.gov/pub/irs-prior/i1040a--2016.pdf
Form1040EZ https://www.irs.gov/pub/irs-prior/i1040gi--2016.pdf
Form 104