If this model is a FineOffset clone with a wifi connected console, as it looks like, you need to set up interceptor to receive the packages what the console would send to one of the providers (ie.: WU).
I don't know that this console can be programmed for specific address like the ObserverIPs, but if not then you need to define a rule in your router to reroute the traffic to your weewx. There are plenty descriptions of this, how to do it with some router firmwares.
I personally have a Eurochron Efws2900, and a Raspberry Pi. The Pi creates an AP where the console connects, and routes the data to WU. The Weewx runs with interceptor set to sniffer mode.
The rest of it is a different story and the previous commenter can help you with that.
I hope it helps!
Gabor