iOS vision framework - Unable to setup request in VNDetectHumanBodyPoseRequest

I use VNDetectHumanBodyPoseRequest to detect body from an image which in xcode assets(I download from image website), But I get error below:

2021-12-24 21:50:19.945976+0800 Guess My Exercise[91308:4258893] [espresso] [Espresso::handle_ex_plan] exception=Espresso exception: "I/O error": Missing weights path cnn_human_pose.espresso.weights status=-2
Unable to perform the request: Error Domain=com.apple.vis Code=9 "Unable to setup request in VNDetectHumanBodyPoseRequest" UserInfo={NSLocalizedDescription=Unable to setup request in VNDetectHumanBodyPoseRequest}.

Below is my codes:

  let image = UIImage(named: "image2")
            guard let cgImage = image?.cgImage else{return}
            
            let requestHandler = VNImageRequestHandler(cgImage: cgImage)

            let request = VNDetectHumanBodyPoseRequest(completionHandler: bodyPoseHandler)

            do {
                // Perform the body pose-detection request.
                try requestHandler.perform([request])
            } catch {
                print("Unable to perform the request: \(error).")
            }


    func bodyPoseHandler(request: VNRequest, error: Error?) {
        guard let observations =
                request.results as? [VNHumanBodyPoseObservation] else {
            return
        }
        
        let poses = Pose.fromObservations(observations)
        
        self.drawPoses(poses, onto: self.simage!)
        // Process each observation to find the recognized body pose points.
    }