I am developing a flight search app using that interacts with the Priceline API through RapidAPI. The problem is that the API is not returning any flight results. I am also receiving a specific error message in the JSON response.

Code doing the API Call:

import Foundation

class FlightService {
  static let shared = FlightService()

  private init() {}

  private func createURLRequest(endpoint: String, parameters: [String: String]?) -> URLRequest? {
    var components = URLComponents(string: "https://priceline-com2.p.rapidapi.com/(endpoint)")

    if let params = parameters {
      components?.queryItems = params.map { URLQueryItem(name: $0.key, value: $0.value) }
    }

    guard let url = components?.url else { return nil }

    var request = URLRequest(url: url)
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    request.addValue("xxxxxxxxxxxxxxxx", forHTTPHeaderField: "X-RapidAPI-Key")
    request.addValue("priceline-com2.p.rapidapi.com", forHTTPHeaderField: "X-RapidAPI-Host")

    return request
  }

  func searchFlightsRoundTrip(origin: String, destination: String, departureDate: String, returnDate: String, passengers: Int, classType: String) async throws -> [Flight] {
    let endpoint = "flights/search-roundtrip"
    let parameters = [
      "originAirportCode": origin,
      "destinationAirportCode": destination,
      "departureDate": departureDate,
      "returnDate": returnDate,
      "numberOfPassengers": String(passengers),
      "classType": classType
    ]

    print("Enviando parámetros a la API: (parameters)")

    guard let request = createURLRequest(endpoint: endpoint, parameters: parameters) else {
      throw URLError(.badURL)
    }

    let (data, response) = try await URLSession.shared.data(for: request)

    if let httpResponse = response as? HTTPURLResponse {
      print("HTTP Status Code: (httpResponse.statusCode)")
    }

    if let jsonString = String(data: data, encoding: .utf8) {
      print("Response JSON: (jsonString)")
    }

    do {
      let flightResponse = try JSONDecoder().decode(FlightResponse.self, from: data)

      if let flights = flightResponse.data?.searchItems {
        print("Flights received: (flights.count)")
        return flights
      } else {
        print("No flights found in the response.")
        return []
      }
    } catch {
      print("Error decoding flight data: (error)")
      throw error
    }
  }
}

Request I am sending to the API:

 {
  "originAirportCode": "MAD",
  "destinationAirportCode": "LON",
  "departureDate": "2024-09-30",
  "returnDate": "2024-10-15",
  "numberOfPassengers": "2",
  "classType": "ECO"
}

The API Response with the following JSON, which seems to indicate an error:

{
  "data": {
    "isFireFly": null,
    "airline": null,
    "airport": null,
    "listings": null,
    "expressDeal": null,
    "filterDefaults": null,
    "listingsMetaData": null,
    "travelInsurance": null,
    "error": {
      "code": null,
      "desc": null,
      "message": "Error while invoking the QueryExecutor.search Operation for component FLY in Error: com.priceline.usp.search.exception.QueryExecutorException: QueryExecutorService.search while calling component FLY, resulted in Error :  No Itineraries Found for Given Request , StatusCode:  ."
    },
    "displayableCarriers": null,
    "expressDealsCandidates": null,
    "brandReference": null
  },
  "meta": {
    "currentPage": 1,
    "limit": 0,
    "totalRecords": 0,
    "totalPage": 0
  },
  "status": true,
  "message": "Successful"
}

Here is the output from the console:

API: ["destinationAirportCode": "LON", "originAirportCode": "MAD", "numberOfPassengers": "2", "classType": "ECO", "departureDate": "2024-09-30", "returnDate": "2024-10-15"]
HTTP Status Code: 200
Response JSON: {"data":{"isFireFly":null,"airline":null,"airport":null,"listings":null,"expressDeal":null,"filterDefaults":null,"listingsMetaData":null,"travelInsurance":null,"error":{"code":null,"desc":null,"message":"Error while invoking the QueryExecutor.search Operation for component FLY in Error: com.priceline.usp.search.exception.QueryExecutorException: QueryExecutorService.search while calling component FLY, resulted in Error :  No Itineraries Found for Given Request , StatusCode:  ."},"displayableCarriers":null,"expressDealsCandidates":null,"brandReference":null},"meta":{"currentPage":1,"limit":0,"totalRecords":0,"totalPage":0},"status":true,"message":"Successful"}
No flights found in the response.

Problem:
Even though I am receiving a 200 OK status from the API, the response data contains no flight itineraries.
The error message in the response is vague: No Itineraries Found for Given Request.

Questions:

• Why am I not getting any flight results from the API, and what does the error No Itineraries Found for Given Request mean in this context?
• Are there any specific changes I need to make to my request parameters to resolve this issue?