How to send my viewmodel to RESTAPI in xamarin andriod mobile app

HttpClient client = new HttpClient();
            var uri = new Uri(string.Format("http://localhost:59803/api/Controller/ActionName?username=" + model.Email + "&Password=" + model.Password));
            HttpResponseMessage response; ;
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            response = await client.GetAsync(uri);
            if (response.StatusCode == System.Net.HttpStatusCode.Accepted)
            {
                var errorMessage1 = response.Content.ReadAsStringAsync().Result.Replace("\\", "").Trim(new char[1] { '"' });
                //Toast.MakeText(this, errorMessage1, ToastLength.Long).Show();
            }
            else
            {
                var errorMessage1 = response.Content.ReadAsStringAsync().Result.Replace("\\", "").Trim(new char[1] { '"' });
                //Toast.MakeText(this, errorMessage1, ToastLength.Long).Show();
            }