Send notification to Reality Composer Pro from iOS project

I am creating an Augmented Reality iOS (Not VisionOS) app using scenes created in Reality Composer Pro.

I'd like my code to send a notification to a RCP scene that plays a timeline. The RCP interface has the option to set up a behaviour for this purpose:

This Forum thread https://developer.apple.com/forums/thread/756978 suggests the code I need for sending a notification is:

  name: NSNotification.Name("RealityKit.NotificationTrigger"),
  object: nil,
  userInfo: [
    "RealityKit.NotificationTrigger.Scene": scene,
    "RealityKit.NotificationTrigger.Identifier": "HideCharacter"
  ]
)

but the 'scene' var needs to point to the relevant RCP scene, which is loaded within a UIViewRepresentable ARView (because even in iOS26 it seems RealityKit/RealityViews aren't quite ready for AR use) and I can't work out how to correctly access it. Examples in the link above are for working with RealityKit and VisionOS only.

Code for loading the scene is as follows. How can I get the notification code above to be situated in a separate SwiftUI View and send the notification to the RCP scene?

    
    typealias UIViewType = ARView
    
    func makeUIView(context: Context) -> ARView {
        
        // Create an ARView
        let arView = ARView(frame: .zero)
        
        // Configure it
        let arConfiguration = ARWorldTrackingConfiguration()
        arConfiguration.planeDetection = [.horizontal]
        arView.session.run(arConfiguration)
        
        // Load in Reality Composer Pro scene
        let scene = try! Entity.load(named:"myScene)", in: realityKitContentBundle)
        
        // Create a horizontal plane anchor
        let anchor = AnchorEntity(.plane(.horizontal, classification: .any, minimumBounds: SIMD2<Float>(0.2, 0.2)))
        
        // Append the scene to the anchor
        anchor.children.append(scene)
        
        // Append the anchor to the ARView
        arView.scene.anchors.append(anchor)
        
        return arView
    }
    
    func updateUIView(_ uiView: ARView, context: Context) {
    }
}