allows showing critical path
webix.ui({
  view: "gantt",
  url: "https://docs.webix.com/gantt-backend/",
  criticalPath: true // enable critical path
});
The property allows to enable critical path. If critical path is enabled, the chain of tasks that cannot be delayed will be highlighted. Such tasks are:
As it is a reactive property you can also access and alter it via the widget state:
// enable critical path
$$("myGantt").getState().criticalPath = true;