To find your animation files and back up your files, please follow the steps below.
Open Run box by pressing "Window + R" command, or by selecting Run from the Start Menu (under Windows System).
Copy and paste below route into the Run box and press OK.
Run will find the target folder and open it. In the folder you will see folders and files as show below. Back up "Projects" folder and "list.adb" file to another destination of your choosing.
After backing up these files, you can reinstall Animation Desk app from the Microsoft App Store. Once the app is reinstalled, you can put these two files back to the same LocalFolder by following the steps above.