Update manage-self-service-sso.mdx (#961)

* Update manage-self-service-sso.mdx

* Update manage-self-service-sso.mdx

Author: nick-gagliardi

main/docs/authenticate/enterprise-connections/self-service-SSO/manage-self-service-sso.mdx

@@ -242,6 +242,7 @@ To generate an access ticket for a new connection through the Auth0 Dashboard:
 3. Under **Ticket configuration**, provide a required name for the connection your customer admin will configure.
 4. In the **Settings** section, configure additional options as needed for the new connection:
 
+   * **Domain**: Select the custom domain to be used in the ticket URL. Only available when multiple custom domains are present.
    * **Display Name**: A user-friendly name for the connection that displays on Universal Login prompts.
    * **Enabled Clients**: A comma-separated list of client IDs to associate with the connection.
    * **Enabled Organizations**: A comma-separated list of organization IDs to associate with the connection.
@@ -285,6 +286,12 @@ To generate an access ticket through the Management API.
 
 `POST  /api/v2/self-service-profiles/{id}/sso-ticket`
 
+<Callout icon="file-lines" color="#0EA5E9" iconType="regular">
+
+Use the `auth0-custom-domain` header to set the custom domain to be used in the ticket URL. This is only available when the Multiple Custom Domains feature is enabled.
+
+</Callout>
+
 In the request body, specify the parameters described in the table below.
 
 | Parameter | Description |