private async Task RefreshCategories()
        {
            BillerCategories = await BillerServices.GetBillerCategories();

            if (BillerCategories != null && BillerCategories.Count > 0)
            {
                BillerCategoryName = new List <string>();
                foreach (var item in BillerCategories)
                {
                    BillerCategoryName.Add(item.Name);
                }
                Category.ItemsSource = BillerCategoryName;
            }
        }
 private async void GetPaymentCategories()
 {
     await Task.Run(() => BillerServices.GetBillerCategories());
 }