Fixes Azure/azure-sdk-for-net#27472

Author: ggailey777

articles/azure-functions/functions-bindings-event-iot-trigger.md

@@ -17,6 +17,17 @@ For information on setup and configuration details, see the [overview](functions
 
 [!INCLUDE [functions-bindings-event-hubs](../../includes/functions-bindings-event-hubs-trigger.md)]
 
+## Connections
+
+The `connection` property is a reference to environment configuration that contains name of an application setting containing a [connection string](#connection-string). Obtain this connection string by selecting the **Connection Information** button for the [namespace](../event-hubs/event-hubs-create.md#create-an-event-hubs-namespace), not the event hub itself. The connection string must be for an Event Hubs namespace, not the event hub itself.
+
+The connection string must have at least "read" permissions to activate the function. 
+
+This connection string should be stored in an application setting with a name matching the value specified by the `connection` property of the binding configuration.
+
+> [!NOTE]  
+> Identity-based connections aren't supported by the IoT Hub trigger.
+
 ## host.json properties
 
 The [host.json](functions-host-json.md#eventhub) file contains settings that control Event Hub trigger behavior. See the [host.json settings](functions-bindings-event-iot.md#hostjson-settings) section for details regarding available settings.