Hi,
in 2D it is possible to add a featureAction in the manifest.json of a custom Widget.
Like this: https://developers.arcgis.com/web-appbuilder/sample-code/create-a-feature-action-in-your-widget.htm
This code doesn´t work in a 3D Widget.
I think the
<SPAN class="string token">"featureActions"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">{</SPAN>
<SPAN class="string token">"name"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"ShowVertex"</SPAN><SPAN class="punctuation token">,</SPAN>
<SPAN class="string token">"uri"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"ShowVertexFeatureAction"</SPAN>
<SPAN class="punctuation token">}</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>