Follow 3 simple steps:
Set up App Impersonation
A Global Admin is required to grant consent to each tenant, and you will need to set up App Impersonation ahead of time.
Enter your Office 365 email address
You will be redirected to the Office 365 login page. When prompted, give 365MobileSync Contact Management consent to allow syncing.
Configure & Sync
Configure your sync processes on the dashboard.