How to integrate online google api in sugarcrm custom drawer?

I want to integrate following google api in to custom drawer. How can I Add following api with script tag in .hbs extensions?

<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js">
</script>

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