using Flurl;
using Flurl.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

      byte[] image = ImagePro.GetImageAsByteArray(txtIdentifyImagePath.Text);
            ByteArrayContent content = new ByteArrayContent(image);

            List<dynamic> response = Settings.UriBase
                                     .AppendPathSegment("detect")
                                     .SetQueryParams(new
                                     {
                                         returnFaceId = "true"
                                     })
                                     .WithHeader("Ocp-Apim-Subscription-Key", Settings.SubscriptionKey)
                                     .WithHeader("Content-Type", "application/octet-stream")
                                     .PostAsync(content)
                                     .ReceiveJson<List<dynamic>>()
                                     .Result;


            foreach (var item in response)
            {
                txtIdentify.AppendText(((JObject)item).ToString() + Environment.NewLine);
                txtIdentify.AppendText("---------------" + Environment.NewLine);
            }

SubscriptionKey-14359e73027d412b96806b7ebf50dabc