Connexion Mattermost to my AD

I just installed Mattermost on an Ubuntu.
I made the first connection with a login and I want to make the connection with my Active Directory but it does not work.
I would like to point out that I took the free 30-day business edition
Can you help me please ?

Talk to an Expert | Mattermost will get you to the correct sales rep. AD/LDAP is supported in the paid versions. Professional provides user synch… allowing you to use a single group to manage Mattermost membership. Enterprise allows group synch, which lets you use multiple groups to manage team and channel membership.

Pricing | Mattermost shows all of the deltas.