drag a modelEntity inside an Immersive space and track position

Goal : Drag a sphere across the room and track it's position

Problem: The gesture seems to have no effect on the sphere ModelEntity. I don't know how to properly attach the gesture to the ModelEntity. Any help is great. Thank you

import SwiftUI
import RealityKit
import RealityKitContent
import Foundation

@main
struct testApp: App {
    @State var immersionStyle:ImmersionStyle = .mixed
    var body: some Scene {
        ImmersiveSpace {
            ContentView()
        }
        .immersionStyle(selection: $immersionStyle, in: .mixed, .full, .progressive)
        
    }
}

struct ContentView: View {
    @State private var lastPosition: SIMD3<Float>? = nil
    @State var subscription: EventSubscription?
    @State private var isDragging: Bool = false
    
   var sphere: ModelEntity {
        let mesh = MeshResource.generateSphere(radius: 0.05)
       let material = SimpleMaterial(color: .blue, isMetallic: false)
        let entity = ModelEntity(mesh: mesh, materials: [material])
       entity.generateCollisionShapes(recursive: true)
        return entity
    }
    var drag: some Gesture {
        DragGesture()
            .targetedToEntity(sphere)
            .onChanged { _ in self.isDragging = true }
            .onEnded { _ in self.isDragging = false }

    }

    var body: some View {
       
            Text("Hello, World!")
        RealityView { content in
            
            //1. Anchor Entity
            let anchor = AnchorEntity(world: SIMD3<Float>(0, 0, -1))
            
            let ball = sphere

            //1.2 add component to ball 
            ball.components.set(InputTargetComponent())
            
            //2. add anchor to sphere
            anchor.addChild(ball)
            
            content.add(anchor)
            
            
            subscription =  content.subscribe(to: SceneEvents.Update.self) { event in
                            let currentPosition = ball.position(relativeTo: nil)
                            if let last = lastPosition, last != currentPosition {
                                print("Sphere moved from \(last) to \(currentPosition)")
                            }
                            lastPosition = currentPosition
            }
            
        }
        .gesture(drag)
    }
    

}