Hi, I've installed and authorised both ArcGIS server and the Utility Network Management extension but the UNME does not show up under GIS Server > Extensions. Is this normal?
From Server Manager, go to Site > Software Authorization and here you should see the roles and extensions that ArcGIS Server is licensed for.
GIS Server > Extensions is where you will find server object extensions (SOEs) and server object interceptors (SOIs). SOEs allow you to create new service operations and SOIs allow you to intercept requests for existing built-in service operations.