All you can do is try. If it doesn't work, and if you used the CD version of TurboTax to complete the 2020 taxes, the .tax2020 file is located in the documents\turbotax directory. Assuming you actually completed your tax return with that specific file, and that you still have TurboTax 2020 installed on your computer, simply open the tax file with TurboTax 2020 and under the file tab elect the option to "print and file". Then print the return for filing. At that point, the program will assume you filed the tax return and the 2021 program will have no problem importing from the 2020 tax file.
