Create a new CheckoutIntent

{
  "checkoutIntent": {
    "id": "<string>",
    "createdAt": "2023-11-07T05:31:56Z",
    "state": "retrieving_offer",
    "productUrl": "<string>",
    "quantity": 123,
    "checkoutHints": "<string>",
    "buyer": {
      "firstName": "<string>",
      "lastName": "<string>",
      "email": "<string>",
      "phone": "<string>",
      "address1": "<string>",
      "address2": "<string>",
      "city": "<string>",
      "province": "<string>",
      "country": "<string>",
      "postalCode": "<string>"
    },
    "shipping": {
      "selectedOptionId": "<string>",
      "availableOptions": [
        {
          "id": "<string>",
          "cost": {
            "amountSubunits": 123,
            "currencyCode": "<string>"
          }
        }
      ]
    },
    "cost": {
      "subtotal": {
        "amountSubunits": 123,
        "currencyCode": "<string>"
      },
      "shipping": {
        "amountSubunits": 123,
        "currencyCode": "<string>"
      },
      "tax": {
        "amountSubunits": 123,
        "currencyCode": "<string>"
      },
      "discount": {
        "amountSubunits": 123,
        "currencyCode": "<string>"
      },
      "total": {
        "amountSubunits": 123,
        "currencyCode": "<string>"
      }
    },
    "tokenizedPaymentCard": {
      "number": "<string>",
      "expiration": "<string>",
      "cvv": "<string>",
      "billingName": "<string>"
    },
    "failureReason": {
      "code": "checkout_intent_expired",
      "message": "<string>"
    }
  }
}