如何将弹出窗口添加到嵌套项内的根ApplicationWindow？

import QtQuick 2.15
import QtQuick.Controls 2.15

ApplicationWindow {
    id: rootWindow
    visible: true
    width: 800
    height: 600
    title: "My Application"
}

Item {
    id: nestedItem
    width: 200
    height: 200
}

Item {
    id: nestedItem
    width: 200
    height: 200

    Popup {
        id: myPopup
        width: 200
        height: 100
        contentItem: Rectangle {
            color: "lightblue"
            Text {
                text: "This is a popup window"
                anchors.centerIn: parent
            }
        }
    }
}

Button {
    text: "Show Popup"
    onClicked: myPopup.open()
}