如何在此Google Maps JavaScript中提醒纬度？

<script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap" async defer></script>

function initMap() {
  var mapOptions = {
    center: { lat: 37.7749, lng: -122.4194 },
    zoom: 8
  };
  var map = new google.maps.Map(document.getElementById("map"), mapOptions);
}

function initMap() {
  var mapOptions = {
    center: { lat: 37.7749, lng: -122.4194 },
    zoom: 8
  };
  var map = new google.maps.Map(document.getElementById("map"), mapOptions);

  var marker = new google.maps.Marker({
    position: { lat: 37.7749, lng: -122.4194 },
    map: map,
    title: "San Francisco"
  });
}

function initMap() {
  var mapOptions = {
    center: { lat: 37.7749, lng: -122.4194 },
    zoom: 8
  };
  var map = new google.maps.Map(document.getElementById("map"), mapOptions);

  var marker = new google.maps.Marker({
    position: { lat: 37.7749, lng: -122.4194 },
    map: map,
    title: "San Francisco"
  });

  var infoWindow = new google.maps.InfoWindow({
    content: "纬度: " + marker.getPosition().lat()
  });

  marker.addListener("click", function() {
    infoWindow.open(map, marker);
  });
}