While we have this integration on the roadmap for the future, how Ambi Climate works currently, doesn't fit within the HomeKit protocol.
For all the coders out there! We have an Open API which some of our users are using to connect HomeKit to Ambi Climate through a Homebridge plugin.
Kudos to Alisdair for his efforts in developing the plugin. Please refer to his github repo here.
For those who that don't have time to customize their own, worry not! Guy, an enthusiastic Ambi user wrote a native macOS app himself, so that connecting to Ambi Climate with Homebridge would be effortless. Checkout his Ambi Bridge here.
Read more about Home Bridge here.