Adding portal example for app service export.

Author: albertofori

articles/azure-app-configuration/howto-import-export-data.md

@@ -464,6 +464,10 @@ From the Azure portal, follow these steps:
 
 You've exported key-values that have the "prod" label from an App Service resource, at their state from 07/28/2021 12:00:00 AM, and have trimmed the prefix "TestApp". The key-values have been exported with a content type in JSON format.
 
+If you checked the box to export key-values as app configuration references, the imported key-values will be indicated as App Configuration references in the "Source" column of your App Service resource configuration settings.
+
+:::image type="content" source="./media/import-export/export-app-service-reference-value.png" alt-text="Screenshot of App Service configuration settings. Exported App Configuration reference in App Service(Portal)."::: 
+
 #### [Azure CLI](#tab/azure-cli)
 
 From the Azure CLI, follow the steps below. If you don't have the Azure CLI installed locally, you can optionally use [Azure Cloud Shell](../cloud-shell/overview.md).