Do a search on your computer for *.tax2019 then double click on the file and see if TurboTax opens it.
If you continue to have problems, please click on the Contact Us form https://support.turbotax.intuit.com/contact/. We’ll help you connect with the right expert for your specific problem.
If you used the Windows Desktop program you need the file ending in .taxyyyy to open in it. The tax files (and PDF files) should be in your Documents then in a Turbo Tax subfolder. If you can't find them do a search for all files ending in .tax or .tax2019, etc. And check the Recycle Bin. For Windows 10 check the One Drive. Did you make any backups? Like DropBox.
If you don't have the main .tax file you might have one that starts with a Tilde sign ~ like "~your name.tax2019". That file is if your computer crashes or your real file gets lost or deleted or corrupt so you can restore it.
Find your Tax file in Windows