Open Street Maps Marker Icon

<html>
<body>
    <div id="mapdiv"></div>
    <script src="http://www.openlayers.org/api/OpenLayers.js"></script>
    <script>
      map = new OpenLayers.Map("mapdiv");
      map.addLayer(new OpenLayers.Layer.OSM());

      let zoom=16;
      let size = new OpenLayers.Size(21,25);
      let offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
      let lonLat = new OpenLayers.LonLat( -81.7692887,26.1741378 ).transform(
      new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
      map.getProjectionObject() // to Spherical Mercator Projection
      );
      map.setCenter (lonLat, zoom);


      let markers = new OpenLayers.Layer.Markers( "Markers" );
      map.addLayer(markers);

      let marker_icon='https://p1.hiclipart.com/preview/365/352/961/simple-linux-logo-black-and-white-penguin-png-clipart.jpg';
      let marker_icon2='https://p7.hiclipart.com/preview/368/650/539/tuxedo-linux-computer-icons-linux.jpg';
      let marker_list=[
        [-81.7680000,26.1741378,marker_icon],
        [-81.7640001,26.1741470],
        [-81.7780000,26.1741378,marker_icon2],
        [-81.7640001,26.1721470]
        ];

      for(m of marker_list){
        addMarker(m[0],m[1],m[2]);
      }

      function addMarker(lon,lat,icon_url){


        let cor = new OpenLayers.LonLat(lon, lat).transform(
        new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
        map.getProjectionObject() // to Spherical Mercator Projection
        );

        if(icon_url !== undefined){
          var icon = new OpenLayers.Icon(icon_url,size,offset);
        }
        markers.addMarker(new OpenLayers.Marker(cor,icon));
      }

    </script>
  </body>
</html>