(AzureCXP)MicrosoftDocs/azure-docs/issues/51420

(AzureCXP) fixed 9th step of Expose an API > Set  in configuring with advanced settings.  
Done repro with previous instructions and found error with multi-tenant app although fine with the single-tenant.
below is the doc enhancement done :-
For single-tenant app, paste in the URL of your App Service app and select Save.
For multi-tenant app, paste in the URL which is based on one of tenant verified domains and select Save.

Author: SnehaAgrawal-MSFT

articles/app-service/configure-authentication-provider-aad.md

@@ -73,7 +73,7 @@ Perform the following steps:
 1. After the app registration is created, copy the **Application (client) ID** and the **Directory (tenant) ID** for later.
 1. Select **Authentication**. Under **Implicit grant**, enable **ID tokens** to allow OpenID Connect user sign-ins from App Service.
 1. (Optional) Select **Branding**. In **Home page URL**, enter the URL of your App Service app and select **Save**.
-1. Select **Expose an API** > **Set**. Paste in the URL of your App Service app and select **Save**.
+1. Select **Expose an API** > **Set**. For single-tenant app, paste in the URL of your App Service app and select **Save** and for multi-tenant app, paste in the URL which is based on one of tenant verified domains and then select **Save**.
 
    > [!NOTE]
    > This value is the **Application ID URI** of the app registration. If your web app requires access to an API in the cloud, you need the **Application ID URI** of the web app when you configure the cloud App Service resource. You can use this, for example, if you want the cloud service to explicitly grant access to the web app.