After you file

Did you check the Recycle bin?  And search your whole computer for files ending in .tax2020.  Where are your backups?

 

Maybe you can find a temp file of it.    If you don't have the main .tax file you might have one that starts with a Tilde sign ~ like  "~your name.tax2020".  That file is if your computer crashes or your real file gets lost or deleted or corrupt so you can restore it.