https://www.esri.com/arcgis-blog/products/sharing-collaboration/sharing-collaboration/how-to-add-a-widget-to-a-configurable-app
How to Add a Widget to a Configurable App
Mar 26, 2018 - Each configurable app in the configurable apps gallery supports a unique set of tools. You can download the source code for each configu...
how to add a widgetconfigurableapp