Map with Marker

HTML

<h3>My Google Maps Demo</h3>
<div id="map"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>

CSS

#map {
  height: 400px;
  width: 100%;
 }

JavaScript

function initMap() {
  var uluru = {lat: 131.044, lng: -25.363};
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 4,
    center: uluru
  });
  var marker = new google.maps.Marker({
    position: uluru,
    map: map
  });
}