Global Key Event QML

[Cinohee]

Hello
There is many bug in QML key event in android

I want to make global Key Event like BackButton
I add key.press in mainwindow and not working
How I can write back button code to navigate between view

   Keys.onReleased: {
        console.log("keyBack")
        if (event.key === Qt.Key_Back) {
            event.accepted = true;
            backPress()
        }
    }

never rise :|
How I could write global key event?