assuming you used desktop when you open the tax file a backup file is created in the same directory as the original. it will start with a "~" if you still have the 2020 program installed you can see if it will open by double clicking on it.
if both files are corrupt, your only option, assuming you filed, is to obtain either a transcript or copy of the return from the iRS
form 4506T = transcript
for 4506 = copy of return for a fee
you can obtain a transcript of the return using the iRS online services.
https://www.irs.gov/individuals/get-transcript
