Add documentation for configuring the home realm identifier

en/includes/guides/authentication/federated-login/index.md

@@ -80,12 +80,18 @@ You can register an external IdP in {{product_name}} by creating a connection. {
 
 {% include "../../fragments/manage-connection/add-groups.md" %}
 
-{% if product_name == "WSO2 Identity Server" %}
+{% if product_name == "WSO2 Identity Server" and is_version <= "7.1.0" %}
+
 ## Add connections to federation hub
 
 {% include "../../fragments/manage-connection/federation-hub.md" %}
+{% else %}
+
+## Configure home realm identifier
+
+{% include "../../fragments/manage-connection/home-realm-identifier.md" %}
 {% endif %}
 
 ## Delete a connection
 
-{% include "../../fragments/manage-connection/delete-connection.md" %}
+{% include "../../fragments/manage-connection/delete-connection.md" %}

en/includes/guides/fragments/manage-connection/home-realm-identifier.md

@@ -0,0 +1,27 @@
+The home realm identifier is a unique value that identifies a connection when routing users directly to a specific external IdP during login. When a user initiates login, your application can include this identifier as the `fidp` query parameter in the authorization request, which causes {{ product_name }} to skip the login page and route the user directly to the specified external IdP.
+
+To configure the home realm identifier:
+
+1. On the {{ product_name }} Console, click **Connections** and select the relevant connection.
+
+2. Go to the **Advanced** tab of the selected connection.
+
+3. Enter a unique identifier in the **Home Realm Identifier** field.
+
+    ![Home realm identifier configuration]({{base_path}}/assets/img/guides/connections/home-realm-identifier.png){: width="600" style="display: block; margin: 0; border: 0.3px solid lightgrey;"}
+
+4. Click **Update** to save the changes.
+
+Once configured, use this identifier in your application's authorization request as follows:
+
+```bash
+https://<host_name>/t/<org_name>/oauth2/authorize?
+  response_type=code
+  &client_id=<client_id>
+  &redirect_uri=<redirect_uri>
+  &scope=openid
+  &fidp=<home_realm_identifier>
+```
+
+!!! note
+    When the `fidp` parameter is provided, {{ product_name }} bypasses the login page and directly initiates the authentication flow with the matching external IdP.