From the documentation App Inventor Extensions: SQlite | Pura Vida Apps
Export database.
Note : Starting with SDK30 Android restricts accessing the file system. Therefore starting from Version 2 of the extension the database will be stored in the ASD - application specific directory /storage/emulated/0/Android/data//files . As fileName just use the filename without slashes.
You then can copy the database to shared storage using the file component... see also Some basics on Android storage system
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