curl -X GET 'https://app.memorylake.cn/openapi/memorylake/admin/v1/billing/payment-methods' \
  -H 'Authorization: Bearer sk_xxxxxx'

{
  "success": true,
  "message": "Operation completed successfully",
  "data": {
    "items": [
      {
        "is_default": true,
        "type": "example",
        "brand": "example",
        "exp_month": 1,
        "exp_year": 1,
        "last4": "example"
      }
    ],
    "continuation_token": "eyJvZmZzZXQiOjIwfQ",
    "total": 1
  }
}