[Qlustar General] QluMan configuration for single sign on

Documentation says: "b) QluMan may be configured to allow for a single sign-on setup where users can be imported from and authenticated against an Active Directory (AD) server." https://docs.qlustar.com/Qlustar/13/ClusterOS/qluman-guide/components/ldap.html#sec-LDAP-Import-Users

How can I configure QluMan this way?

I have configured sssd on the head node to connect to our AD (ldap + kerberos), but in QluMan, "Components > LDAP > Import Users > From AD" is disabled (gray).

Thanks,

João