add LineOfSight custom widget into appbuilder 2.16 for esri ArcGIS (Developer Edition)

Question

I'm new to this area. I succeeded in adding 2d ListView widget by following esri tutorials, but will appreciate some help in adding the 3d LineOfSight custom widget into appbuilder 2.16 for esri ArcGIS (Developer Edition)

Answer 1

I succeeded to do it right by properly attaching the LineOfSight to the htmnl.