Case Files should always be stored in the corresponding app specific folder in the On My iPad location. The “path” that many computer users may be able to relate to is: iPad / Files / On My iPad / [AppName].
If you open the Files app on your iPad you will see a list of Locations available to store files in the left column. One of this locations is On My iPad, and inside that location should be specific folders for each app. TrialPad Case Files should be stored in the TrialPad folder, TranscriptPad Case Files should be stored in the TranscriptPad folder, and DocReviewPad Case Files should be stored in the DocReviewPad folder.