How to hide a button in the Optimus's toolbar?

Hi sir,

How do I hide a button in the Optimus toolbar below?

https://dhtmlx.com/docs/products/demoApps/dhtmlxExam/#exams

this.on(“view:editExam”, id => {
this.show(TopView, ConfigWindow, {
action: “edit”,
item: this.exams.getItem(id),
});
// I want to Hide id:“addButton” button here.
});

Please, try to use the hide() method of the dhx.Toolbar:
https://docs.dhtmlx.com/suite/toolbar/api/toolbar_hide_method/