can't render the gannt chart

[alonbentura]

Error: Element ref was specified as a string (bar) but no owner was set. This could happen for one of the following reasons:

1. You may be adding a ref to a function component

2. You may be adding a ref to a component that was not created inside a component's render method

3. You have multiple copies of React loaded
   See https://reactjs.org/link/refs-must-have-owner for more information.

   "react": "^17.0.2",
   "react-dom": "^17.0.2",
   "react-gantt": "^2.1.8",
   "moment": "^2.29.1",