I have a Philps Hue Motion sensor

I'm really new to hubitat hub.
so far I have my Philps Hue Motion sensor programed into the hubitat hub, I can see its working on hubitat web interface when I put my hand in front of the motion sensor.

I would like to get this motion sensor to tell Blue Iris to record an alert, if anyone knows an easy way and can explain to someone new at this that would be great, I hate the blue iris false alerts and this is why I want to do it this way.
thank you kindly

Can I just clarify that you mean your motion sensor is directly paired to your Hubitat hub via Zigbee, not paired to a Hue hub and showing into Hubitat system via a hub integration?

I don't use blue iris but I would start with installing this app and configuring and then using the motion from the HUE motion sensor to switch the recording on.

Yes that's correct

in Rule Machine:

Trigger: motion detected

Action: make HTTP get request, here is where you find the URL structure to tell Blue Iris to start recording:

Download the Hubitat app