I've never heard of that. You can save the .tax2023 file anywhere. It will not turn a .tax yyyy file into a pdf. How did you do the save? The .tax2023 has to be somewhere on your computer. The default is in your Documents in a TurboTax folder. Search your whole computer for all files ending in .tax or .tax2023, etc. Check in One Drive, Drop Box, etc. Windows has a habit of moving your files to One Drive.
If you don't have the main .tax file you might have one that starts with a Tilde sign ~ like "~your name.tax2023". That file is if your computer crashes or your real file gets lost or deleted or corrupt so you can restore it.
Can you start the 2023 program and open your return? In the 2023 program do a File-Save AS and give it a easy name you can find or search for. And note where it saves it or select where to save it so you can find it again.
