403 Forbidden - Daily quota reached or API key unauthorized

Team

I am also getting Error “Daily quota reached or API key unauthorized!” . Please find the uploaded screen shot for reference.

My Input Latitude and Longitude is : {locations:[[8.609168, 49.893230],[8.589405, 50.055435]]}

var baseAddress = new Uri(“https://api.openrouteservice.org”);
string responseData = “”;
using (var httpClient = new HttpClient { BaseAddress = baseAddress })
{
httpClient.DefaultRequestHeaders.Accept.Clear();
httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue(“application/json”));
httpClient.DefaultRequestHeaders.Authorization =new AuthenticationHeaderValue(“Authorization”, “xxx”);

            var SensorLocationsData = _notiUnitOfWork.NotificationRepository.GetLastSensorLocationData();
            string locations = "{locations:[locs]}";
            string loc = string.Empty;
            foreach (var SensorLocations in SensorLocationsData)
            {
                string str = string.Format("[{0}, {1}]", SensorLocations.Longitude, SensorLocations.Latitude);
                if (str != "")
                    loc += str + ","; 
            }

            locations = locations.Replace("locs", loc.Substring(0, loc.Length - 1));
            using (var content = new StringContent(locations))
            {
                using (HttpResponseMessage response = httpClient.PostAsync("/v2/matrix/driving-car", content).Result)
                {
                    responseData = response.Content.ReadAsStringAsync().Result;
                }
            }
        }
        string jsonString = JsonConvert.SerializeObject(responseData);
        return new JsonResult() { Data = jsonString, JsonRequestBehavior = JsonRequestBehavior.AllowGet };

Thanks,
Vamsi