OptionalbrandOptionalexpirationOptionalexpirationOptionallast4OptionalwalletDigital wallet the card was added through, e.g. apple_pay, google_pay. null when no wallet information is
available, so it doesn't prove the card is a regular one: cards saved before this field existed have no value.
Card brand as reported by the billing provider, e.g.
visa,mastercard,amex.nullwhen not available.