Initializing Google APIs serverside in MVC controller

Question

I have this code in my MVC Controller:

[HttpGet]
[OutputCache(VaryByParam = "*", Duration = 3600, Location =  System.Web.UI.OutputCacheLocation.ServerAndClient)]
public async Task<string> GetAPI(string callback, string libraries)
{
    var location_selector_script = System.IO.File.ReadAllText(Server.MapPath("~/Scripts/nav/locselector.js"));
    var res = await Utilities.API.GetAsync("https://maps.googleapis.com/maps/api/js?key=" + ConfigurationsHelper.GoogleMapsAPIKey
                + "&callback=" + callback + "&libraries=" + libraries);
            return res + location_selector_script;
}

and call it like this:

<script async defer src="/Navigation/GetAPI?callback=initMap&libraries=places"></script>

Is this a good idea to initialize Google APIs in backend?