No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3000' is therefore not allowed access

I have an ASP.NET Web API 2 app (hosted in Azure) and a front-end in Angular JS. When I try to call any of my controller methods I am getting the following error:

XMLHttpRequest cannot load https://........ No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3000' is therefore not allowed access. This is how my Configuration code looks in the Startup class.

public void Configuration(IAppBuilder app) { // setup cors policy var corsPolicy = new CorsPolicy { AllowAnyOrigin = true, //AllowAnyHeader = true, //AllowAnyMethod = true,
SupportsCredentials = true };

        // add headers
        foreach (var hdr in new string[] { "Authorization", "Content-Type", "Origin", "X-Requested-With", "Accept", "Cache-Control" }) { corsPolicy.Headers.Add(hdr); }

        // add methods
        foreach (var mth in new string[] { "GET", "POST", "PUT", "DELETE", "OPTIONS" }) { corsPolicy.Methods.Add(mth); }

        // add origins
        var allowedOrigins = ConfigurationManager.AppSettings["AllowedOrigins"];
        if (allowedOrigins != null)
        {
            var origins = allowedOrigins.Split(',').Select(x => x.Trim());
            if (origins.Any())
            {
                if (!origins.Contains("*"))
                {
                    corsPolicy.AllowAnyOrigin = false;

                    // add each whitelisted origin
                    foreach (var origin in origins) { corsPolicy.Origins.Add(origin); }
                }
            }
        }

        // setup cors options
        var corsOptions = new CorsOptions
        {
            PolicyProvider = new CorsPolicyProvider { PolicyResolver = context => Task.FromResult(corsPolicy) }
        };

        // enable cors
        app.UseCors(corsOptions);


        // setup JWT tokens auth
        ConfigureOAuthTokenGeneration(app);
        ConfigureOAuthTokenConsumption(app);


        var httpConfig = new HttpConfiguration();

        ConfigureWebApi(httpConfig);

        app.UseWebApi(httpConfig);

    }