Position real time (Firebase)

Ionic Framework ionic-v3
1

Hello guys, I have one table User

User
id
name
email
latitude
longitude

where I would like update position of the user in real time in my home.ts I have the following code

addPosition() {
    let watch = this.geolocation.watchPosition();
    watch.subscribe((data) => {

      this.myPosition = new google.maps.LatLng(data.coords.latitude, data.coords.longitude);

          this.mapOptions = {
            zoom: 19,
            center: this.myPosition,
            disableDefaultUI: true
          }

          this.map = new google.maps.Map(document.getElementById('map'), this.mapOptions);
          this.directionsDisplay.setMap(this.map);

          this.addMarker(this.myPosition);

          const request = {
                origin: this.myPosition,
                destination: new google.maps.LatLng('-1.376040', '-48.435644'),
                travelMode: 'DRIVING'
              };

              this.traceRoute(this.directionsService, this.directionsDisplay, request);

    })
  }

how I can update method in Firebase ?