I use Web AppBuilder (Develper Edtion) 2.17, Launchpad Theme, on 3D Scenes (ArcGIS API for javascript 4.16).
I need that mouse right click on feature will open my custom widget, with info on the feature clicked.
There is an example that might be relevane - How to make a menu on right click of feature on feature layer
but I don't know how to get it to work on esri javascript 4.16
