Provides struct and type for a CheckoutLinkUpdate
@type t() :: %Polarex.CheckoutLinkUpdate{ allow_discount_codes: boolean() | nil, discount_id: String.t() | nil, label: String.t() | nil, metadata: Polarex.Metadata.t() | nil, products: [String.t()] | nil, require_billing_address: boolean() | nil, success_url: String.t() | nil }