The objective of this task is to grant FreeBusy the OAuth permissions to necessary access calendars for people in your Office 365 tenant. Consent could be given by individual users (if domain policy is set to allow them to give consent) or by an admin on behalf of the users. This task covers the latter option.
Task needs to be performed by someone who is an admin for the Office 365 tenant.
1. Use this link to initiate a sign in request with admin consent:
Sign In For Admin Consent
2. On that page, use click on the "Sign In With Office 365" button
3. After entering your admin credentials grant the requested permissions:
Note: It’s benign if you go through the process multiple times or if multiple admins do it.