Zen Thermostat Fan Control

Is there any way to enable a fan control trigger for a smart app. For example, allow a smart app to set the fan control to “On” when a temp sensor hits a certain threshold. So far I have only been able to control the temperature or Heat/Cool mode via a smart app.

I’m pretty sure you just need to set the "device.thermostatFanMode = ‘fanOn’ but I’m not 100% on that.