@type t() :: %Polarex.SeatAssign{
  checkout_id: String.t() | nil,
  customer_id: String.t() | nil,
  email: String.t() | nil,
  external_customer_id: String.t() | nil,
  immediate_claim: boolean() | nil,
  metadata: map() | nil,
  order_id: String.t() | nil,
  subscription_id: String.t() | nil
}