curl --request GET \
  --url https://api.sandbox.zafapay.com/v1/customers/{customer_id}/payment-methods \
  --header 'Authorization: Bearer <token>'

{
  "customer_id": "cust_abc123",
  "payment_methods": [
    {
      "id": "pmi_abc123",
      "type": "card",
      "card": {
        "brand": "visa",
        "last4": "4242",
        "exp_month": 12,
        "exp_year": 2028,
        "cardholder_name": "TARO YAMADA",
        "country": "JP",
        "funding": "credit"
      },
      "is_default": true,
      "status": "active",
      "created_at": "2024-01-15T10:30:00.000Z"
    }
  ]
}