Activating Azure Rights Management for Office 365

https://technet.microsoft.com/library/jj658941.aspx

https://support.office.com/en-za/article/Activate-Rights-Management-RMS-in-the-Office-365-admin-center-5b6d3ac7-b1ac-428e-b03e-50e882f85a6e

1. expand SERVICE SETTINGS.
2. Click Rights Management.