How to predefine demo import properly? Please help

In my theme . i have included one click demo import and predefined imports which will get three files from my hosting , 2. widget.wie , 3 .customizer.dat . Is this correct method or i have to include these files in my theme and get files from my theme . My current coding for predefine import is
‘import_file_name’ => ‘Demo Import loptus’,
‘import_file_url’ => ‘’,
‘import_widget_file_url’ => ‘’,
Is this method correct