I found this functionality in the ArcGIS API for JavaScript sample code and want to use it in WAB Developer Edition (LayerList widget with actions | ArcGIS API for JavaScript 4.8 ). I am new to working with JavaScript and was wondering where in the LayerList widget to add the code in the previous link so that it functions as it does in the link.
layerlist layerlist widget radio button javascript api 4.8 #wab for dev
The problem is that the WAB widgets (for the 2D apps) are built using the 3.x API, which doesn't have this capability built-in. Eventually, the code will be rewritten so everything uses the 4.x API, but that's not expected until at least next year.