OpenLayers demo to useAnchor option in ol.interaction.MouseWheelZoom

<!DOCTYPE html>
<html>
  <head>
    <meta charset=utf-8>
    <meta name=description content="">
    <meta name=viewport content="width=device-width, initial-scale=1">
    <title>Simple Map with default interactions</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v4.6.4/css/ol.css" type="text/css">
    <style>
      html, body {
        height: 100%;
        padding: 0;
        margin: 0;
      }
      #map {
        width: 100%;
        height: 60%;
      }
    </style>
    
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestanimationframe,element.prototype.classlist,url"></script>
    <script src="https://openlayers.org/en/v4.6.4/build/ol.js"></script>
  </head>
  <body>
    <div id="map" class="map"></div>
    <label for="mouse-anchor">
      Mouse anchor when using wheelzoom
      <input id="mouse-anchor" type="checkbox" checked="checked">
    </label>
    <script>
      const defaultInteractions = ol.interaction.defaults();
      const mouseWheelInteraction = defaultInteractions.getArray().find(el => el instanceof ol.interaction.MouseWheelZoom);
      const map = new ol.Map({
        interactions: defaultInteractions,
        layers: [
          new ol.layer.Tile({
            source: new ol.source.OSM()
          })
        ],
        target: 'map',
        view: new ol.View({
          center: [0, 0],
          zoom: 2
        })
      });

document.getElementById('mouse-anchor').addEventListener('change', function() {
        mouseWheelInteraction.setMouseAnchor(this.checked);
      });
    </script>
  </body>
</html>

Updated missing url https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL to https://cdn.polyfill.io/v2/polyfill.min.js?features=requestanimationframe,element.prototype.classlist,url

https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL

https://openlayers.org/en/v4.6.4/build/ol.js