overlayControl is not defined

trying to use Gantt chart with overlay in console always throws this at me
chartjs.js? v = 09eyasljL86nOaG59dSKGNfNUZogbD_clejQMI6FZlw: 3 Reference error not caught: overlayControl not defined
in toggleOverlay (chartjs.js? v = 09eyasljL86nOaG59dSKGNfNUZogbD_clejQMI6FZlw: 3)

I already tried several things but the overlayControl is always defined

Hello Dan,
You need to make sure that the chart.js file is connected and loaded. Here is a simple example with the Chart.js library usage inside the Gantt overlay:
https://snippet.dhtmlx.com/5/711d3c2b7