@type t() :: %Polarex.DiscountFixedCreate{
  amount: integer() | nil,
  amounts: map() | nil,
  code: String.t() | nil,
  currency: String.t() | nil,
  duration: String.t(),
  duration_in_months: integer() | nil,
  ends_at: DateTime.t() | nil,
  max_redemptions: integer() | nil,
  metadata: map() | nil,
  name: String.t(),
  organization_id: String.t() | nil,
  products: [String.t()] | nil,
  starts_at: DateTime.t() | nil,
  type: String.t() | nil
}