@type t() :: %StripeElixir.Params.CouponCreateParams{
  amount_off: integer() | nil,
  applies_to: map() | nil,
  currency: String.t() | nil,
  currency_options: map() | nil,
  duration: String.t() | nil,
  duration_in_months: integer() | nil,
  expand: [String.t()] | nil,
  id: String.t() | nil,
  max_redemptions: integer() | nil,
  metadata: map() | nil,
  name: String.t() | nil,
  percent_off: float() | nil,
  redeem_by: integer() | nil
}