Sorry there is no way to trick it to use a 2020 file. Can't you find the .tax2021 file like in TimeMachine or a backup? It should not have lost your current 2022 file. I think sometimes Mac saves it in a place that's buried.
How to find tax files on Mac
https://ttlc.intuit.com/questions/1901659-find-your-tax-data-file-in-mac
