There was some discussion of that over here: Synchronize Ring Alarm Keypad v2 with Alarmo - #10 by andrew3
Apparently, a newer firmware version does expose it. Presumably the official ring base station knows how to download a new firmware image, but I don’t have one to test with. They don’t seem to make it freely available, and I haven’t tried asking their tech support. I tend to doubt that they’d just send it over, but it might be worth a try if it’s a feature that you want.