I've found an example on how to do this for asp.net core, but this does not work with blazor.
<script>
$("#diagram").ejDiagram({
constraints: ej.datavisualization.Diagram.SelectorConstraints.All & ~(ej.datavisualization.Diagram.SelectorConstraints.Rotator | ej.datavisualization.Diagram.SelectorConstraints.Resizer)
});
</script>