vários marcadores no google maps do banco de dados firebase

<!DOCTYPE html>
<html>
  <head>
    <title>Geolocation</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <style>
      /* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
      #map {
        height: 100%;
      }
      /* Optional: Makes the sample page fill the window. */
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
    </style>
    <!-- Place this inside the HTML head; don't use async defer for now -->
<script src="https://www.gstatic.com/firebasejs/4.12.1/firebase.js"></script>
<script src="https://cdn.firebase.com/libs/geofire/4.1.2/geofire.min.js"></script>

  <script>
        
        var config = {
    apiKey: "AIzaSyCWZjRe2CK8Hu2VN35AgZOQ7lQZKcI-UWM",
    authDomain: "carrier-35d7c.firebaseapp.com",
    databaseURL: "https://carrier-35d7c.firebaseio.com",
    projectId: "carrier-35d7c",
    storageBucket: "carrier-35d7c.appspot.com",
    messagingSenderId: "827792028763"
  };
        if (!firebase.apps.length) {
            firebase.initializeApp(config);
        }
        
        //Create a node at firebase location to add locations as child keys
        var locationsRef = firebase.database().ref("locations");
        
        // Create a new GeoFire key under users Firebase location
        var geoFire = new GeoFire(locationsRef.push());
      </script>


  </head>
  <body>
    <div id="map"></div>
    <script>
      // Note: This example requires that you consent to location sharing when
      // prompted by your browser. If you see the error "The Geolocation service
      // failed.", it means you probably did not give permission for the browser to
      // locate you.
      var map, infoWindow;
      var lat, lng;
      function initMap() {
        map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: -34.397, lng: 150.644},
          zoom: 18
        });
        infoWindow = new google.maps.InfoWindow;
        // Try HTML5 geolocation.
        if (navigator.geolocation) {
          navigator.geolocation.getCurrentPosition(function(position) {
            lat = position.coords.latitude;
            lng = position.coords.longitude;
            var pos = {lat: lat, lng: lng };
                _setGeoFire();
              var locationsRef = firebase.database().ref("locations");
locationsRef.on('child_added', function(snapshot) {
  var bounds = new google.maps.LatLngBounds(); // declaration 
var data = snapshot.val();
var marker = new google.maps.Marker({
  position: {
    lat: data.lat,
    lng: data.lng
  },
  map: map
});
bounds.extend(marker.getPosition());
marker.addListener('click', (function(data) {
  return function(e) {
    infowindow.setContent(data.name + "<br>" + this.getPosition().toUrlValue(6) + "<br>" + data.message);
    infowindow.open(map, this);
  }
}(data)));
map.fitBounds(bounds);
});
          
            infoWindow.setPosition(pos);
            infoWindow.setContent('Location found.');
            infoWindow.open(map);
            map.setCenter(pos);
          }, function() {
            handleLocationError(true, infoWindow, map.getCenter());
          });
        } else {
          // Browser doesn't support Geolocation
          handleLocationError(false, infoWindow, map.getCenter());
        }
      }
      function handleLocationError(browserHasGeolocation, infoWindow, pos) {
        infoWindow.setPosition(pos);
        infoWindow.setContent(browserHasGeolocation ?
                              'Error: The Geolocation service failed.' :
                              'Error: Your browser doesn\'t support geolocation.');
        infoWindow.open(map);
      }
      function _setGeoFire(){
    geoFire.set("User", [lat, lng]).then(()=>{
            console.log("Location added");
        }).catch(function(error) {
            console.log(error);
        });
}
    </script>
    <script 
    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyD2nPlSt_nM7PSKD8So8anbUbBYICFWcCA&callback=initMap">
    </script>
  </body>
</html>

Preciso de ajuda para plotar vários pontos de coordenadas do meu banco de dados em tempo real do firebase em um mapa do google. Estou usando o geofire para sincronizar a localização atual do usuário no banco de dados. Outro usuário de estouro de pilha me deu algum código para usar e eu o coloquei no meu programa, mas por algum motivo, funciona para eles, mas não funciona para mim.Como exibir várias coordenadas de marcadores armazenadas no banco de dados Firebase no Google Maps. Esse é o link para a pergunta que fiz algumas semanas atrás. Se alguém puder me ajudar a descobrir por que isso não está funcionando, eu realmente aprecio

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