To add the room resources from Office 365 to Room Booking, you need to assign the correct permissions to the user. To set correct permissions to the delegate user in Office 365 please follow the instructions below.
1. Go to https://admin.microsoft.com/#/ResourceMailbox and locate the room resource you are trying to add to the Room booking portal
2. Under Delegates, click on edit and add the Office 365 user you wish for calendar access.
3. The permissions need some time to be assigned in Office 365; therefore, we recommend waiting for 24 hours.
4. Add the assigned user to Room Booking by moving to Settings -> Calendar and login in as the Office 365 user.
Please note: This user needs to have at least the Business Office 365 Licence
5. After 24 hours, you will be able to add the room resource in the Room Booking portal. To add, please navigate to Manage -> Rooms -> Add a Room and click on "Autoscan rooms" or "Add a room" to add the room resources manually.
In case you receive the following error: “You don't have permissions to read and write to this room resource” then you have not waited long enough or have not set the delegation correctly.