[Flutter]: FAB For Only One Bottom Tab

I have a BottomAppBar that has a FloatingActionButton. However, I only want this button to be seen in one particular screen. In the best case, I'd like to add this button only when the user clicks on that particular screen.

I've found that you can add a FAB like this:

return Scaffold(
      extendBodyBehindAppBar: true,
      extendBody: true,
      floatingActionButtonLocation: FloatingActionButtonLocation.endDocked,
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          ...
        },
        child:  const Icon(
          Icons.add_sharp,
          color: Color(0xFFFFFFFF),
        ),
      ),
      body: Center(
        child: _widgetOptions.elementAt(_selectedIndex),
      ),
      bottomNavigationBar: buildBottomNavigationBar(),
    );

However, as you can see this Scaffold is shared by all the screens that can be selected in the bottomNavigationBar. How do I add a FAB only for a particular screen?

I'd like the FAB to be embedded into the bottomNavigationBar so I do not want to add a plain button to that particular screen. Thanks.

Turns out the solution was actually quite simple and I was overthinking stuff. I have a variable that keeps track of the currently open screen. So I simply added this little logic to the mother screen that hosts the bottomNavigationBar:

if (_selectedIndex==1){
  // Other screen that needs the FAB
  return Scaffold(
    ...,
    floatingActionButton: FloatingActionButton(
        ....
    ),
    bottomNavigationBar: buildBottomNavigationBar(),
  );
}

return Scaffold(
  ...,
  bottomNavigationBar: buildBottomNavigationBar(),
);