I saw a demo here: https://docs.dhtmlx.com/gantt/samples/11_resources/04_resource_usage_diagram.html?_ga=2.81895830.160995991.1619430496-1302080179.1619169743
and I couldn't found API support for the resource panel in your document.
Does the react-dhtmlx-gantt provide limited functions compare to the non React dhtmlx-gantt?