Detecting images with unspecified size

Code Block class ViewController: UIViewController {
   
  @IBOutlet var arView: ARView!
  fileprivate var configuration: ARWorldTrackingConfiguration!
  fileprivate var rootAnchor: AnchorEntity!
   
  // MARK: === viewWillAppear
  override func viewWillAppear(_ animated: Bool)
  {
    super.viewWillAppear(animated)
     
    configuration = ARWorldTrackingConfiguration()
    configuration.automaticImageScaleEstimationEnabled = true
    configuration.detectionImages = ARReferenceImage.referenceImages(inGroupNamed: "AR Resources", bundle: nil)
    arView.session.run(configuration)
  }
  // MARK: === viewDidLoad
  override func viewDidLoad() {
    super.viewDidLoad()
     
    arView.session.delegate = self
  }
}
// MARK: === ARSessionDelegate
extension ViewController: ARSessionDelegate
{
  func session(_ session: ARSession, didAdd anchors: [ARAnchor])
  {
    anchors.compactMap { $0 as? ARImageAnchor }.forEach {
       
      rootAnchor = AnchorEntity()
      rootAnchor.transform.matrix = $0.transform
      arView.scene.addAnchor(rootAnchor)
       
      add()
    }
  }
  func session(_ session: ARSession, didUpdate anchors: [ARAnchor])
  {
    anchors.compactMap { $0 as? ARImageAnchor }.forEach {
       
      rootAnchor.transform.matrix = $0.transform
    }
  }
  // MARK: === add
  fileprivate func add()
  {
    let audioPlane = MeshResource.generatePlane(width: 0.2, height: 0.2, cornerRadius: 0)
    var audioMtl = SimpleMaterial()
    do {
      audioMtl.baseColor = try MaterialColorParameter.texture(TextureResource.load(named: "audio_play.png"))
    } catch {
    }
    let audioEy = ModelEntity(mesh: audioPlane, materials: [audioMtl])
    audioEy.position = [0, 0.1, 0]
    rootAnchor.addChild(audioEy)
  }
}