The only copy of your .tax2019 file is on the computer you used to file your tax return, and any backup copies that you made. TurboTax does not have a copy of it.
TurboTax will not automatically find the file if it has been moved since you saved it. If it doesn't show up when you start TurboTax, look first in the TurboTax folder. That's the default location. The file name extension is .tax2019, not .tax. If you don't find it in the TurboTax folder, use the Windows search to search your entire hard drive for *.tax2019.
You should always save a PDF of your tax return in addition to the .tax20yy file. The only way to open the .tax20yy file is with the TurboTax software for the corresponding year. At some point in the future you might no longer have a working copy of the software. Then the PDF is the only way to see your tax return.
