I am wondering if it is possible to add Esri vector basemap/tile layer to my Web AppBuilder basemap widget. I am using custom zoom scales and the precached basemaps wont work, however the vector basemaps do. Does the esri vector basemap group make the service url to these basemaps available similar to the default basemaps. For example if I wanted to add the Dark Grey Canvas basemap to the widget I would fill out the dialog box below and use the service url.
http://services.arcgisonline.com/arcgis/rest/services/Canvas/World_Dark_Gray_Base/MapServer

However I cant seem to find the service url for the vector tile maps the only url I see exposed is
https://basemaps.arcgis.com/b2/arcgis/rest/services/World_Basemap/VectorTileServer
but this link isn't accepted by the dialog box. Is there a service url for each vector basemap?
