<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        var path = new kendo.dataviz.diagram.Path({
          data: "M 80 0 C 100 0 100 0 100 20 L 100 80 C 100 100 100 100 80 100 L 20 100 C 0 100 0 100 0 80 L 0 20 C 0 0 0 0 20 0Z",
          fill: "red"
        });
        group.append(path);
        console.log("Drawing element:", path.drawingElement);
        return group;
      }
    }]
  });
</script>