Creating Change Button in QGC To Change Alt

I Create a UI button for changing Alt in QGC but it doesent work …
how can I solve this object …
help me
thanks

its the code that i have written

import QtQuick 2.12
import QtQuick.Controls 2.4
import QtQuick.Dialogs 1.3
import QtQuick.Layouts 1.12

import QtLocation 5.3
import QtPositioning 5.3
import QtQuick.Window 2.2
import QtQml.Models 2.1

import QGroundControl 1.0
import QGroundControl.Airspace 1.0
import QGroundControl.Airmap 1.0
import QGroundControl.Controllers 1.0
import QGroundControl.Controls 1.0
import QGroundControl.FactSystem 1.0
import QGroundControl.FlightDisplay 1.0
import QGroundControl.FlightMap 1.0
import QGroundControl.Palette 1.0
import QGroundControl.ScreenTools 1.0
import QGroundControl.Vehicle 1.0
import QtQuick.Layouts 1.2
import QtQuick.Controls 2.5
import QtQuick 2.11
import QtQuick.Layouts 1.11
import QGroundControl.FactControls 1.0
import QtQuick 2.3
import QtQuick.Controls 1.2
import QtQuick.Controls.Styles 1.4
import QtQuick.Dialogs 1.2
import QtQml 2.2
import MAVLink 1.0

property var _activeVehicle: QGroundControl.multiVehicleManager.activeVehicle

QGCButton {
id: alb
height: 50
width:50
anchors.right: parent.right
checkable: true
onClicked:_activeVehicle.sendCommand(1,186,true,700,3)
visible: true
background:
Rectangle{
id: alr
color:“red”
opacity: alb.checked ? 1 : .9
}
}