I need to file a 2021 tax return

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.

If you completed a 2021 tax return using the TurboTax online editions you can print and mail the tax return.

To access your current or prior year tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

Scroll down to the section Your tax returns & documents.  Click on the Year and Click on Download/print return (PDF)

A 2021 tax return can only be printed and mailed, it cannot be e-filed.

Print, sign, date and mail the tax return to the IRS.  Include with the mailed return any forms W-2 and 1099 which have taxes withheld.  Go to this IRS website for mailing addresses - https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment

There are no penalties for filing a tax return after the due date if filing for a tax refund or there are no taxes owed.

Why did it reject?  A common reason is the wrong AGI.   Do you need to change anything?   Sorry you can't efile 2021 anymore, it's too late.  You have to print and mail prior year returns.  

How to Access prior year online returns
https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/27010

If you can't get the side menus to open up to access the prior year..... You need to start entering some basic Personal Info in 2022 for the side menu to open up. Just continue a little ways into 2022. I had to go though about 12 screens.

Have you filed 2022 yet?  When you efile 2022 you will need to enter 0 for the AGI since you are filing 2021 late.