Like many I am trying to migrate to AdvancedMarkerElement in Google Maps Javascript API.
I have followed the documentation and so far have:

<script defer src="https://maps.googleapis.com/maps/api/js?key={{env("GOOGLE_JAVASCRIPT_APIKEY")}}&loading=async&callback=gmapinit&v=weekly&libraries=marker"></script>

then further for the callback:

async function gmapinit() {//used as callback,required by the api when loading it
      const {AdvancedMarkerElement} = await google.maps.importLibrary("marker");
      const {PinElement} = await google.maps.importLibrary("marker");
      GMap = new G_Map();//own wrapper class
}

Successfully working is a basic AdvancedMapMarker on the map with:

  let marker = new google.maps.marker.AdvancedMarkerElement({
        map: this.map, position: markerposition, title: title,
      });
      let iconImg = document.createElement("img");
      iconImg.src = optargs.icon;
      marker.content = iconImg;

However there is no scaling for the image here, which I would like to do programmatically.
So attempting to change the above to

  let iconImg = document.createElement("img");
  iconImg.src = optargs.icon;
  let pin = new PinElement({
    scale: 1.5,
    content: iconImg,

  });
  let marker = new google.maps.marker.AdvancedMarkerElement({
    map: this.map, position: markerposition, title: title,
    content: pin.element
  });

Is where the error occurs with:

ReferenceError: PinElement is not defined

So my question is how do I load PinElement to code as per the examples – I am obviously missing something simple somewhere