you have included javascript api multiple times in this page error

[shreetam24]

Hi,
I have added js file manually by downloading because I was getting "google not defined" error. But because to pass the api key i have to pass <script async defer src="https://maps.googleapis.com/maps/api/js?key=my_key">
</script> in index.html. So I get the error "you have included javascript api multiple times in this page error". Is there any other way I can pass the key than calling the api ?