NAO CONECTA EM SERVICO REST

[Activity(Label = [Ô]App1[Ô], MainLauncher = true, Icon = [Ô]@drawable/icon[Ô])]
public class MainActivity : Activity
{
    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        // Set our view from the [Ô]main[Ô] layout resource
        SetContentView(Resource.Layout.Main);

        FindViewById<Button>(Resource.Id.button1).Click += MainActivity_Click;
    }

    private async void MainActivity_Click(object sender, System.EventArgs e)
    {
        /*var handler = new HttpClientHandler
        {
            Proxy = new WebProxy([Ô]192.168.0.30[Ô], 8888),
            UseProxy = true
        };*/

        using (var client = new HttpClient(/*handler*/))
        {

            using (var tokenResponse = await client.PostAsync([Ô]http://euroribeirao.ddns.net:1200/Api_escola/api/token[Ô], CreateContent()))
            {
                HttpStatusCode Status = tokenResponse.StatusCode;
                if (Status.ToString() != [Ô]404[Ô])
                {
                    var tokenBody = await tokenResponse.Content.ReadAsStringAsync();
                    //parsedTokenBody = JsonConvert.DeserializeObject(tokenBody);
                }
            }
        }
    }

    private static FormUrlEncodedContent CreateContent()
    {
        return new FormUrlEncodedContent(new[]
        {
            new KeyValuePair<string, string>([Ô]grant_type[Ô], [Ô]password[Ô]),
            new KeyValuePair<string, string>([Ô]username[Ô], [Ô]teste[Ô]),
            new KeyValuePair<string, string>([Ô]password[Ô], [Ô]teste1234[Ô])
        });
    }
}