The On-site Interview event will be automatically added to your Outlook calendar after a Candidate confirms the interview time.
Here is the flow of how the integration of MS Outlook works:
1. HR Manager set up an On-site interview with the candidate
2. Candidate receives an email notification about the upcoming event
3. Candidate follows the link from the invitation email and confirms the scheduled time
4. HR Manager receives the time confirmation email and the event will be automatically added to the Outlook calendar
Also, read How to Add On-site (Offline) Interview to Outlook Calendar?