ScrollBar not working in scrollview.

[Fakhr]

I'm new to qml and most of my code consists of examples from official documentation and online examples. I've created a scrollview in which there is a rectangle with column and in the column there are multiple buttons. I tried inplementing a scrollbar because the content will be bigger than the container , but the scrollbar does not work any help would be appreciated.
My code is as follow:

import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.15
import QtGraphicalEffects 1.15

Window {
width: 740
height: 580
visible: true
color: "#00000000"
title: qsTr("Hello World")

Rectangle {
    id: rectangle
    color: "#40405f"
    anchors.fill: parent

    Button {
        id: button
        text: qsTr("Menu")
        anchors.left: parent.left
        anchors.top: parent.top
        anchors.bottom: parent.bottom
        anchors.leftMargin: 10
        anchors.bottomMargin: 466
        anchors.topMargin: 74
        onClicked: animationMenu.running = true
    }

    ScrollView {
        id: scrollView
        width: 0
        anchors.left: button.right
        anchors.top: parent.top
        anchors.bottom: parent.bottom
        anchors.leftMargin: 10
        anchors.bottomMargin: 10
        anchors.topMargin: 10
        clip: true

        Rectangle {
            id: rectangle1
            color: "#00000000"
            border.color: "#00000000"
            border.width: 0
            anchors.fill: parent

            PropertyAnimation {
                id: animationMenu
                target: scrollView
                property: "width"
                to: if(scrollView.width == 0) return 240; else return 0
                duration: 800
                easing.type: Easing.InOutQuint
            }

            Column {
                id: columnMenu
                width: 0
                anchors.fill: parent
                spacing: 10

                Button {
                    id: button1
                    text: qsTr("Button")
                }

                Button {
                    id: button2
                    text: qsTr("Button")
                }

                Button {
                    id: button3
                    text: qsTr("Button")
                }

                Button {
                    id: button4
                    text: qsTr("Button")
                }
            }
        }

        ScrollBar {
            id: vbar
            hoverEnabled: true
            orientation: Qt.Vertical
            size: scrollView.height / rectangle1.height
            anchors.top: parent.top
            anchors.right: parent.right
            anchors.bottom: parent.bottom
            wheelEnabled: true
            pressed: true
            active: true
        }
    }
}
}