You cannot combine your 2021 return with your 2022 return. The online version is only to prepare a 2022 return.
To file a 2021 return with TurboTax, you would need the 2021 Desktop software. (it installs on your computer) Your return would have to be printed, signed, & mailed. You can purchase the 2021 software from TurboTax at the following website:
https://turbotax.intuit.com/personal-taxes/past-years-products/
If you choose you can still e-file your 2022 by entering a Zero (0) for your 2021 AGI since you are filing a 2021 late.
