Back button wp 8.1

cocos2d-x JavaScript
1

Hi,
I am not able to handle the back button on js. I am using cocos2d-x 3.6.1

I have this to code to handle it:

onKeyReleased: function (key, event) {
    var target = event.getCurrentTarget();
    switch(key) {
        case cc.KEY.back:
            csky.WindowManager.getInstance().openWindow(csky.WindowType.WINDOW_EXIT_GAME);
            if (csky.UserDataManager.getInstance().isCoolDownTimeAds()) {
                target.runAction(cc.sequence(cc.delayTime(0.5), cc.callFunc(target.showBanner, target)));
            }
            break;
        case cc.KEY.home:
            csky.SoundManager.getInstance().stopMusic(); 
            break;
        case cc.KEY.escape:
            csky.WindowManager.getInstance().openWindow(csky.WindowType.WINDOW_EXIT_GAME);
            break;
    }
    event.stopPropagation();
}

The home and backbutton works well on android but not in wp.
I read this: https://msopentech.com/blog/2015/04/23/how-to-handle-the-windows-phone-8-1-back-button-in-cocos2d-x-v3-6/
For this I use the key escape to handle the back on wp.
But the listener it’s not called so it’s not a case of which key is the right. I have checked that in the cpp is implemented but it’s like the event does not get to the js part.