Deploy the add-in to your users' Outlook mailboxes in the Microsoft 365 admin center.
The link uploads the add-in in the Microsoft 365 admin center.
This add-in works only for Exchange Online users protected by Cloud App Security.
Wait a few minutes for the deployment to complete.
According to Microsoft, it can take up to 24 hours for a newly deployed add-in to appear on the app ribbon in your users' Outlook mailboxes. Your users may need to relaunch Office to view the add-in icon on the app ribbon.