The Outlook calendar integration is not a sync. Instead, it works by sending a meeting request to the default email, added in the Settings section of the backend, every time an inspection is moved to the Scheduled status.
From the Company Settings page, fill in the "Calendar request email" field with the email attached to the calendar you'd like the inspections to be added to
Click Save when done
>>> NOTE: Going forward, every time an inspection is moved to scheduled, a calendar appointment for that date and time will be sent to the calendar associated with the email in the Settings section.