A payment method saved on the account's Stripe customer (read-only here; manage in the dashboard).
Card brand, lowercase ("visa", "mastercard", …); empty for non-card methods.
Identifying email for account-style methods (e.g. Link); null otherwise.
Card last four; empty for non-card methods.
Stripe PaymentMethod type: "card", "link", …
A payment method saved on the account's Stripe customer (read-only here; manage in the dashboard).