Unable to Consume Web Api in Xamarin

Question

var keyValues = new List<KeyValuePair<string, string>>

{

new KeyValuePair<string, string>("username", UserName),

new KeyValuePair<string, string>("password", Password),

new KeyValuePair<string, string>("grant_type", "password")

};

var request = new HttpRequestMessage(HttpMethod.Post, "http://softstacksolutions.in/Token");

request.Content = new FormUrlEncodedContent(keyValues);

var client = new HttpClient();

var response = await client.SendAsync(request);

var jwt = await response.Content.ReadAsStringAsync();

JObject jwtynamic = JsonConvert.DeserializeObject<dynamic>(jwt);

var accessToken = jwtynamic.Value<string>("access_token");

return accessToken;

 

this code works fine on simulator but faild but app crashes while this code is called

 

why?