Manage user access to add-ins for Outlook in Exchange Online

Specify the administrators and users who can install and manage add-ins for Outlook in Exchange Online

You can specify which administrators in your organization have permissions to install and manage add-ins for Outlook. You can also specify which users in your organization have permission to install and manage add-ins for their own use.

Determine if Centralized Deployment of add-ins works for your organization - Microsoft 365 admin

Determine if your tenant and users meet the requirements, so that you can use Centralized Deployment to deploy Office Add-ins.

User not seeing add-ins - Microsoft 365

Learn how to help your users troubleshoot centralized add-ins, if they are not seeing them.