Android Question B4A How do I copy a data file at installation of the app

'Copies a database file that was added in the Files tab. The database must be copied to a writable location.
'This method copies the database to the storage card. If the storage card is not available the file is copied to the internal folder.
'The target folder is returned.
'If the database file already exists then no copying is done.
Sub CopyDBFromAssets (FileName As String) As String
    
    Try
    
        Dim TargetDir As String
    
        If File.ExternalWritable Then
            TargetDir = DBFileDir
        Else
            TargetDir = File.DirInternal
        End If
    
        If File.Exists(TargetDir, FileName) = False Then
            File.Copy(File.DirAssets, FileName, TargetDir, FileName)
        End If
    
        Return TargetDir
    
    Catch
        Log("CopyDBFromAssets " & LastException.Message)
        
        Return ""
    End Try
    
End Sub