Configure resources via OWA
In Options → Resource scheduling, you can manage scheduling options as well as scheduling permission.
Scheduling options: Here you can manage the options for the scheduling options.
Scheduling permissions: Here you can select the user and groups, that can get access to the resource planning.
To process incoming invitations and cancellations automatically, please check the corresponding option in the field Scheduling options.
Please note that due to a bug you need to save the changes two times.
The option to add user is next to the information of the meeting.
This options is available when you have created a meeting.