I've just managed to setup Zigbee2MQTT and your plugin. Seems to be working, but now I'm having same troubles.
I have only one Zigbee device and that's a Frient KEPZB-110 alarm keypad.
I want to use this to arm/disarm my alarm system.
When I define this as model "Scene (Rotary)", the alarm action is received in Indigo.
So pressing the arm, disarm, night buttons shows these actions in the action property of the device.
To properly use this device, I also need to receive the "action_code". That field will contain the "PIN-code" that is needed to disarm the alarm.
See https://www.zigbee2mqtt.io/devices/KEYZB-110.html for details.
How can this be done?