Are Bookings synchornized with 2-way sync with external services?
If you use external services such as Booking.com or Airbnb to sell your booking products, you need to prevent overbookings. To avoid your booking products to be overbooked, you can synchronize their availability with your calendar. Through the option Booking sync available in the product edit page, you can import ICS calendars by adding the external services names and URL.
You can find an example of how to do this at this link