<style>
#map {
        height: 100%;
      }
</style>
<div id="map"></div>
<script>
      var map;
      function initMap() {
        map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: -34.397, lng: 150.644},
          zoom: 8
        });
      }
    </script>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCpuq8oxHVGT3pPPKE7gvz0IdSgsZUwiR4&callback=initMap"
    async defer></script>