"FlutterWindowManager.FLAG_SECURE' not working for screen shots

[ghost]

I'm using flutter_windowmanager 0.2.0 but nothing will happen, just it helps me to hide the screen.
How to prevent to take screen shots and also not hide the app logo ?

My code :

   void secureScreen() async {
    await FlutterWindowManager.addFlags(FlutterWindowManager.FLAG_SECURE);
    await FlutterWindowManager.addFlags(
        FlutterWindowManager.FLAG_KEEP_SCREEN_ON);
    await FlutterWindowManager.addFlags(FlutterWindowManager.FLAG_FULLSCREEN);
  }

  @override
  void initState() {
    super.initState();
    secureScreen();
  }

this is my code in main.dart

My Screenshot - https://drive.google.com/file/d/1zudi1VeJXJKIEjB3cNDhH2TB7ddxeUnx/view?usp=sharing