I can not add HBook calendar into TripAdvisor. Why? What can I do?

TripAdvisor has recently introduced new rules about the ICals that can be added to their listings. This means only TripAdvisor agents are able to add HBook calendar to the TripAdvisor calendar for now. Please get in touch with TripAdvisor support team and they will be able to assist you and add HBook calendars to your TripAdvisor listing.