HOW TO: using the stopScreensaver() command on TILEBOARD?

I’m trying to figure out how to use the stopScreensaver command. I’m running HASSIO with Tileboard on Raspberry and have a button on my touchscreen UI that opens up a full-screen camera stream when pressed (see below). This works fine. But when pressing the button, I’d like to stop the screensaver so that the camera video remains on the screen until I close the pop-up. When the full-screen pop-up closes, I’d like to automatically re- startScreensaver().

Can someone share a complete code snipit please?

{
 position: [0, 0],
 id: 'camera.camera4',
 type: TYPES.CAMERA_THUMBNAIL,
 bgSize: 'cover',
 title: 'Camera 4',
 width: 2,
 state: false,
 fullscreen: {
   type: TYPES.CAMERA_STREAM,
   objFit: 'contain',
   bufferLength: 5
                   },
 refresh: function () { // can also be a function
    return 3000 + Math.random() * 1000
}