public void OnLogin(object o, EventArgs e)
{
TokenProvider tokenProvider = new TokenProvider("https://ecoupon.bdms.co.th/eCouponApi/Token", txtUserName.Text, txtPassword.Text);
var token1 = tokenProvider.GetToken();
JObject information = JObject.Parse(token1);
Token tt = information.ToObject <Token>();
Token t = JsonConvert.DeserializeObject <Token>(token1);
ApiProvider apiProvider = new ApiProvider("https://ecoupon.bdms.co.th/eCouponApi/api/couponsNew", t.token_type, t.access_token);
txtToken.Text = apiProvider.CallApi();
}