Single Sign On on UCS application not working

From Univention Corporate Server (UCS) you need to be logged at least once on each application even though you already logged to the UCS. So where is the SSO here ? can someone tell us how to activate it ?
Kind regards,
Jean-Raoul Agathe

For someone whom may want to know.
The SSO is supported for UCS applications. However, application from the app catalog liek OX are not supported. You need a SAML authentication for any applications which need the provider procedure of the application.