Can I upload my 2020 and 2021 tax returns completed with Turbo Tax desktop version?

[ee-ea]

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/find-last-year-tax-data-file-...

[xmasbaby0]

Upload them to what?   If you mean you want to store them in your online account, no, you cannot use your online account to store the returns you prepared using the CD/download.  Those returns are stored locally on the hard drive of the computer you used, or on any back up device you used like a flash drive.  They are not stored online with returns you may have prepared using online software in past years.  So---make sure you save hard copies too, or you could find yourself having to pay the IRS for copies someday.