$w("#audioPlayer") not working

Here is a simple page of the site. https://www.musicbooknet.com/bach-for-guitar-music-scores

and here is the code on this page:

$w.onReady(function () {
});
export function repeater1_itemReady($item, itemData, index) {
	 $w("#slider2").onChange((event) => {
   $item = $w.at(event.context);
    $item("#audioPlayer2").volume=event.target.value
   })
}

The audioplayer in the repatear1 gets its mp3 url from the dataset. If i moved the audioplayer out of the repeater and set the volume etc programatically, again does nothing (so it seems the repeater is not the problem).