To keep your availability up to date across multiple booking platforms, export your Houfy calendar as an iCal feed.
Steps to export your Houfy calendar
Go to Manage Listings, open the listing, and click Calendar.
Click Export in the calendar toolbar. The Export Calendar window opens with two tabs.
Stay on the Houfy Reservations tab - it exports only the bookings made on Houfy, which is what other platforms should import.
Click Copy URL.
Go to the other platform (Airbnb, VRBO, Booking.com) and paste the URL into their calendar import field.
Do not send them the Master Calendar tab's URL. That feed also contains the reservations Houfy imported from those platforms, so importing it back makes a platform re-import its own bookings.
Tip: import each platform's calendar into Houfy as well, so the sync runs both ways.