Check your decklaration on site. To load the Google Maps JavaScript API, use a script tag like this
<script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap"
async defer></script>
I using this declaration on my Wordpress site in function.php file
wp_enqueue_script("google-maps-v3", "//maps.google.com/maps/api/js?key=YOUR_API_KEY", false, array(), false, true);
I have set API key on this format, and its works fine
http://my-domain-name(without www).com/*
this declaration not working
*.my-domain-name.com/*