You have to do each year separately. In TurboTax Online enter only your 2021 information.
You cannot use TurboTax Online to file for 2020. TurboTax Online is only for the current tax year, which is now 2021. To file for 2020 you have to use the CD/Download TurboTax software for 2020. You can purchase a download at the following link. There is no free filing for past years.
Past Years' Products
You might get a better price from a reputable online seller that still has TurboTax for 2020 in stock.
The CD/Download TurboTax software can only be used on a Windows or Mac computer, not on a mobile device or a Chromebook.
Tax returns for past years cannot be e-filed. You will have to print your 2020 tax return, sign it, and file it by mail.
