How to create shape using clipper in flutter?

Question

Unable to create such curvy shape like in image attachment using CustomClipper. Can anyone can help?

class Customshape extends CustomClipper<Path>{
  @override
  Path getClip(Size size) {
    double height = size.height;
    double width = size.width;

    var path = Path();
    path.lineTo(0, height-50);
    path.quadraticBezierTo(width/2, height, width, height-50);
    path.lineTo(width, 0);
    path.close();
    return path;
  }

  @override
  bool shouldReclip(covariant CustomClipper<Path> oldClipper) {
    return true;
  }

} 

CustomWidget.dart

return Scaffold(
  appBar:  AppBar(
    toolbarHeight: 130,
    backgroundColor: Colors.transparent,
    elevation: 0.0,
    flexibleSpace: ClipPath(
      clipper: Customshape(),
      child: Container(
        height: 250,
        width: MediaQuery.of(context).size.width,
        color: Colors.green,
        child: Center(child: Text("CustomClipper test", style: TextStyle(fontSize: 40, color: Colors.white),)),
      ),
    ),
  ),
   body: Container(),
);