Here is the code for a simple app with a bottom navigation bar:

MaterialApp(
  home: Scaffold(
    body: Container(color: Colors.red),
    bottomNavigationBar: BottomNavigationBar(
      backgroundColor: Colors.green,
      items: [
        BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
        BottomNavigationBarItem(icon: Icon(Icons.search), label: 'Search')
      ],
    ),
  ),
);

For some reason the bottom navigation bar does not overlap the bottom system notch:

How can I fix this so the bottom navigation overlaps the system’s bottom navigation button?