Detection Not calling in IOS #53

mounted() {
      LocalNotifications.requestPermission().then(() => {
        this.sendNotification('Starting scan', 'Scan your cards')
        this.initMLKit()
      })
    }
.......
initMLKit() {
        const image = new MLKitView();
        image.cameraPosition = CameraPosition.Front
        image.detectionType = DetectionType.Text
        image.torchOn = true

        image.requestCameraPermission().then(() => {
          console.log(image.detectionType)
          image.on('detection', this.onDetection)
        });
      },
      onDetection(event) {
        alert(event)
        if(event.type === DetectionType.Image){
          const text = event.data;
          this.sendNotification('Card recognized', event.data)
       }
      }
    }