Okay, think I have it. Here’s the response:
So to answer the original question. If you want to use a mains powered PIR to trigger ST then you can use a Fibaro Relay (the FGS-212 replaced the FGS-211).
In my case I’ll be using it without any load (my lights will be Hue bulbs in a different location). I’ll be using the motion detector to trigger the relay and then use ST to turn lights on/off/up/down.
the fact that this will be located high, won’t require batteries, needs along range (12m) drives the requirement.
Thanks for the pointer @Alwas