[MNT-24470] Add Note to reflect that Basic Auth with Identity Service…

…s is no longer supported (#1607)

process-services/latest/config/authenticate.md

@@ -13,6 +13,8 @@ The authentication methods that can be configured for Process Services are:
 
 Process Services can be configured to authenticate using the [Identity Service]({% link identity-service/1.2/index.md %}).
 
+>**Note:** Starting from Alfresco Process Services 24.1, basic authentication is no longer supported when `activiti.identity-service.enabled` is set to `true`, as part of replacing Keycloak adapter with Spring security. This includes access to the REST APIs, for which you will first need to obtain a token from Identity Services.
+
 The Identity Service allows you to configure user authentication between a supported LDAP provider or SAML identity provider and the Identity Service for Single Sign On (SSO) capabilities.
 
 The Identity Service needs to be [deployed]({% link identity-service/1.2/install/index.md %}) and [configured]({% link identity-service/1.2/config/index.md %}) with an identity provider before being set up with other Alfresco products.

process-services/latest/develop/rest-api.md

@@ -22,6 +22,8 @@ You can use any of the following methods for REST API user authentication:
 * [OAuth 2 SSO](#oauth-2-sso-overview)
 * Impersonation
 
+>**Note:** Starting from Alfresco Process Services 24.1, basic authentication is no longer supported when `activiti.identity-service.enabled` is set to `true`, as part of replacing Keycloak adapter with Spring security. This includes access to the REST APIs, for which you will first need to obtain a token from Identity Services.
+
 If you are using basic authentication, you must set all requests with the `Authorization` header.
 
 If you are using OAuth 2 to authenticate users for SSO, see [OAuth 2 SSO](#oauth-2-sso-overview) for more information.