Two way sync with Google Calendar
Under WP Admin > BookingRobin > Providers > provider detail page > Calendar Sync section, check Enable calendar sync.
Click grant authorization,
Click Google, input your account email address
Allow BookingRobin to access your calendar.
and then copy the generated code to Authorization Code field, and click update.
Once it is added, you are able to choose your personal calendar to sync with. Do not forget to click save before leaving the page.