Hi Berbere,
Thank you for sharing the link. I had reviewed this link but here they have given the coordinate values from relayoutData callback.
I am specially looking the x and y axes values, which range user has selected. Suppose on x-axes we have months and y-axes we have $ value. And if user selected 3-months graph area then we have to display those 3 months name somewhere on the graph (or popup).
I hope we can do this by adding some JavaScript or with any available functionality.
Thanks