How to trigger scene custom behaviour in Xcode 15

Question

I'm working on an AR App. With Reality Composer and Xcode 14 I was triggering custom behaviours from with just:

myScene.notifications.myBox.post() called from

let myScene = try! Experience.loadBox()

Now in Xcode 15 I don't have an Experience instead with the .reality file I have to use Entities so now I've tried to call:

let objectAR = try! Entity.load(named: "myProject.reality")

But at this point I can't access the "Scene"

How can I trigger my previously Reality Composer exported custom behaviour from that ?