Booking.com allows only one channel manager connection. If you are already using a channel manager to manage your listings, you will have to deactivate it on the Booking.com interface and then add Smartbnb as a channel manager in order to set up the integration.
Can I keep using my channel manager for Booking.com and use Smartbnb on top of it to manage communication with my guests?
No, it's not currently possible. Due to the nature of our integration with Booking.com, you need to choose Smartbnb as your channel manager in order to import your listings. Since only one channel manager connection is allowed for your Booking.com properties, any existing channel manager connection has to be deactivated.