Please follow the instructions in this TurboTax Help article to prepare and file your tax return for 2021.
To complete and file a 2021 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2021 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2021 tax return can only be printed and mailed, it cannot be e-filed using TurboTax.
Sorry it's too,late to start a 2021 online return or use the mobile app, either on Turbo Tax or the IRS. And too late to efile 2021. If you need to do 2021 you can buy the Desktop download here,
TurboTax 2021 Prior Year Tax Prep - File Past Years' Taxes
You will need a full Windows or Mac to install it on.
If you have a simple return and want to file for free you can fill out the forms by hand. Here are some basic forms.....
Here is the 2021 1040 return
https://www.irs.gov/pub/irs-prior/f1040--2021.pdf
or if you want bigger type use 1040SR for Seniors,
https://www.irs.gov/pub/irs-prior/f1040s--2021.pdf
2021 1040 Instructions
https://www.irs.gov/pub/irs-prior/i1040gi--2021.pdf
2021 EIC and Tax Tables
https://www.irs.gov/pub/irs-prior/i1040tt--2021.pdf
Schedules 1-3
https://www.irs.gov/pub/irs-prior/f1040s1--2021.pdf
https://www.irs.gov/pub/irs-prior/f1040s2--2021.pdf
https://www.irs.gov/pub/irs-prior/f1040s3--2021.pdf
Don’t forget your state. And you will have to print and mail your returns. So be sure to attach copies of your W2s and any 1099s that have withholding on them. You have to mail federal and state in separate envelopes because they go to different places. Get a tracking number from the post office when you mail them for proof of filing.