Add alert box to Mendix sso

Author: Karuna-Mendix

content/en/docs/marketplace/platform-supported-content/modules/mendix-sso.md

@@ -1,13 +1,22 @@
 ---
 title: "Mendix SSO"
 url: /appstore/modules/mendix-sso/
+deprecated: true
 description: "Describes the configuration and usage of the Mendix SSO module, which is available in the Mendix Marketplace."
 #If moving or renaming this doc file, implement a temporary redirect and let the respective team know they should update the URL in the product. See Mapping to Products for more details.
 #Please do not rename the anchor #supplements in this document as it is used in links from the module release notes.
 ---
 
 ## Introduction
 
+{{% alert color="warning" %}}
+This module is deprecated as of May 1, 2026, and will be removed from the public Marketplace on November 1, 2026.  
+
+To ensure uninterrupted single sign-on functionality for end users, Mendix recommends migrating to the [OIDC SSO](/appstore/modules/oidc/) module, which requires configuring an identity provider (IdP). 
+
+If an external IdP is not available, you may alternatively use local in-app credentials or implement a custom SSO solution using the [OIDC Provider](/appstore/services/oidc-provider/) module.
+{{% /alert %}}
+
 With the [Mendix SSO](https://marketplace.mendix.com/link/component/111349/) module, you can utilize single sign-on functionality by directly integrating with the Mendix identity provider and leveraging the [OpenID Connect](https://openid.net/connect/) framework.
 
 This module allows end-users to sign in with their Mendix account with the click of a button, instead of requiring their local user credentials. This module avoids having to deal with local user management or password reset flows for the test and acceptance phases of your app development.