validate if [card] payment method already exists using fingerprint

[fernan542]

Describe the bug
How can I validate if card already exists or attached to customer? Because as of now, the customer can add many Cards with the same details. I've read in some SDKs / Library that we can check it using the payment_method's fingerprint but I'm not able to see it when I access the Card properties.

Card properties:

/// Card data associated with the payment method
class Card with _$Card {
  @JsonSerializable(explicitToJson: true)
  const factory Card({
    /// The brand associated to the card e.g. (visa, amex).
    String? brand,

    /// Two letter iso code.
    String? country,

    /// four digit number representing the year of expiry of the card.
    int? expYear,

    /// two digit number representing the month of expire of the card.
    int? expMonth,

    /// card funding type e.g. (credit, debit).
    String? funding,

    /// last four digits of the card.
    String? last4,
  }) = _Card;

  factory Card.fromJson(Map<String, dynamic> json) => _$CardFromJson(json);
}

• Package version: 2.4.0
• Flutter version 2.10.3

My temporary solution is to use the last4 property of the given card.