This forces the game to scan your folders and register the new map when it boots up.
Android 11 and newer restrict access to the Android/data folder for security. To bypass this, connect your phone to a Windows PC via a USB cable, set the connection to "File Transfer", and move the files using your PC's file explorer.
The Content Store offers professionally created routes from around the world. For example, 3DZUG released the "Alpensee" (Alpine Lake) payware route for Trainz Simulator 3 in March 2022, showcasing the quality of official add-on content.