I cannot find any details of their protocol other than that they seem to refer to it as ITC - Intelligent Technical Control.
Since it is using an app on a smartphone and hence traffic will go over WiFi your best approach is to examine the traffic and see if you can understand it. Other than capturing all network traffic and filtering you could look at configuring the smartphone to use a proxy server, the proxy server could then capture the specific traffic. There is a free tool specifically designed for this sort of situation of wanting to examine the app conversation.
See - https://mitmproxy.org/
I could not find any examples of smart home integrations for Faber not even using Home Assistant so you will have to create one once you have captured and understood its traffic.