@type t() :: %Paypal.Subscription.Plan.PaymentPreferences{
  auto_bill_outstanding: boolean() | nil,
  payment_failure_threshold: integer() | nil,
  setup_fee: Paypal.Common.CurrencyValue.t() | nil,
  setup_fee_failure_action: any() | nil
}

Payment preferences:

• auto_bill_outstanding - Whether to automatically bill outstanding amount in next cycle.
• setup_fee - Initial setup fee amount.
• setup_fee_failure_action - Action if setup fee fails (:continue or :cancel).
• payment_failure_threshold - Number of failed payments before subscription is suspended.