Zibgee for communication with robot

[Rocky170500]

Hey,

I wanted to use Zigbee and Zigbee2MQTT application on my robot. As in I wanted to send some signal or I wanted to toggle a flag in my robot using Zigbee with a button. For example, I want to have zigbee coordinator which is stand alone and keeps running all the time, I want to have my robot connect with it (I have some idea that we can do it with help of usb ports available on my robot) and I want to have a button or remote or application like thing in my hand which I press and my robot receives the information that button is pressed. Can someone please help to figure out how can I do this, as per my knowledge I need a coordinator and an end device in my robot. But what is coordinator and end devices and how to buy them or from where I am confused also how can I integrate Zigbee2MQTT in it. Thanks in advance for the help and guidance.