Thank you for your answer @Emma ! The agent is now working and i add the microsoft 365 channel. I can add the agent and talk with him from my side, but when I share the agents with my colleagues, they cannot talk with him. 
I already gave permissions to my colleagues in unity catalog, schema and table, in cluster and in genie. I also add the user in a security group and add this group to the permissions in the channels tab. 
What is missing? 

Thank you!