Didn't you save a pdf file of it? Do you just have the .tax2020 file? If you can't install the program you could try the TaxPrinter service to convert a .tax file to pdf at
https://www.taxprinter.com
They might be expensive and it is probably not safe to email tax returns back and forth. They are not related to Turbo Tax. I don't know if they can do State.
You need your 2020 AGI to efile 2021. The AGI is on 2020 1040 line 11. If you filed a Joint return you use the same AGI for each spouse.
How to find the AGI.
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947
If you didn't file 2020 or filed it later in the year or mailed it, then try entering 0 for the AGI. If that doesn't work you will have to print and mail your return.
Or request a transcript from the IRS
https://www.irs.gov/individuals/get-transcript
