interactiveOverlay is dismissable even "interactiveOverlayDismissable=false" on start up video

I am working on a project with video background.

I am following this guild (Listing 8-2)

https://developer.apple.com/library/content/documentation/TVMLKitJS/Conceptual/TVMLProgrammingGuide/PlayingVideo.html

Apply this interactiveOverlayDocument with a document, and the interactiveOverlayDismissable = false; statement.

https://developer.apple.com/documentation/tvmljs/player/2123044-interactiveoverlaydismissable

Like this:

App.onLaunch = function(options) {
    var singleVideo = new MediaItem('video', 'http:/
    var videoList = new Playlist();
    videoList.push(singleVideo)
    var myPlayer = new Player();
    myPlayer.playlist = videoList;

    var parser = new DOMParser();
    var parsedDoc = parser.parseFromString(`<document>
                                           <alertTemplate>
                                           <button>
                                           <text>Click Me</text>
                                           </button>
                                           </alertTemplate>
                                           </document>`, "application/xml");

    myPlayer.interactiveOverlayDocument = parsedDoc;
    myPlayer.interactiveOverlayDismissable = false;

    myPlayer.play();
}

However, when I launch the app, and press menu button, the button went away and the interactiveOverlay is dismissed.

Wondering if I am missing something here.