DART

flutter back button with data

WillPopScope(
      onWillPop: () async {
        Navigator.pop(context, 'Pass Your Data Here');
        return false;
      },
      child: // Your Widget
);

flutter back button

onPressed: () {
  Navigator.pop(context);
}

send data back on back press flutter

leading: IconButton(icon:Icon(Icons.chevron_left),onPressed:() => Navigator.pop(context, false),),)