Choice of equipment for an automatic staircase

Configuration
5

I found this model that seems suitable :

SONOFF SNZB-03 / SNZB-03P – Zigbee motion sensor with ambient light detection, compatible with Alexa, Google Home, Home Assistant, MQTT and SmartThings.

However, I don’t yet know what to use to control the lamp.
I’m torn between two options :

  • Find a lamp with built-in Zigbee
  • Or install a module (box) behind the existing lamp

So I found this: SONOFF - Zigbee switch module 10A ZBMINIR2

Can I put it behind the ceiling lamp ?

result :