private async void ExecuteGerarTokenCommand()
        {
            try
            {
                var token = await StoneService.GerarToken();

                if (token != null && token.success)
                {
                    Token             = token.data.token;
                    AppSettings.Token = Token;
                }
                else
                {
                    Token = "Erro ao gerar o token!";
                }
            }
            catch (Exception ex)
            {
                await Application.Current.MainPage.DisplayAlert("Informação", ex.Message, "OK");
            }
        }