how to push all content up when open keyboard
You can simply give the widget a bottom position of MediaQuery.of(context).viewInsets.bottom if you are using a stack.
In your case, set margin : to MediaQuery.of(context).viewInsets.bottom instead of padding.
showModalBottomSheet( context: context, isScrollControlled: true, builder: (BuildContext context) { return Container( padding: EdgeInsets.only( bottom: MediaQuery.of(context).viewInsets.bottom, ), child: //your code ); })This works for me. Maybe try moving your padding inside the container.