Use native Swift API for HTTP request with auth proxy

I'm simply trying to use a proxy to route a http request in Swift. I've tried using a URLSession Delegate but that results in the same issue with the iOS menu.

proxy format: host:port:username:password

When I run the code below I am prompted with a menu to add credentials for the proxy. I closed this menu inside my app and tried the function below again and it worked without giving me the menu a second time. However even though the function works without throwing any errors, it does NOT use the proxies to route the request.

I've spent days on this and the only solution I found was using a NWConnection but this is super low level and now I need a shared session to manage cookies. If you want to see the NWConnection solution I made its here

func averageProxyGroupSpeed(proxies: [String], completion: @escaping (Int, String) -> Void) {
    let numProxies = proxies.count
    if numProxies == 0 {
        completion(0, "No proxies")
        return
    }

    var totalTime: Int64 = 0
    var successCount = 0
    let group = DispatchGroup()
    let queue = DispatchQueue(label: "proxyQueue", attributes: .concurrent)
    let lock = NSLock()

    let shuffledProxies = proxies.shuffled()
    let selectedProxies = Array(shuffledProxies.prefix(25))

    for proxy in selectedProxies {
        group.enter()
        queue.async {
            let proxyDetails = proxy.split(separator: ":").map(String.init)
            guard proxyDetails.count == 4,
                  let port = Int(proxyDetails[1]),
                  let url = URL(string: "http://httpbin.org/get") else {
                completion(0, "Invalid proxy format")
                group.leave()
                return
            }

            var request = URLRequest(url: url)
            request.timeoutInterval = 15

            let configuration = URLSessionConfiguration.default
            configuration.connectionProxyDictionary = [
                AnyHashable("HTTPEnable"): true,
                AnyHashable("HTTPProxy"): proxyDetails[0],
                AnyHashable("HTTPPort"): port,
                AnyHashable("HTTPSEnable"): false,
                AnyHashable("HTTPUser"): proxyDetails[2],
                AnyHashable("HTTPPassword"): proxyDetails[3]
            ]

            let session = URLSession(configuration: configuration)
            let start = Date()

            let task = session.dataTask(with: request) { _, _, error in
                defer { group.leave() }
                
                if let error = error {
                    print("Error: \(error.localizedDescription)")
                } else {
                    let duration = Date().timeIntervalSince(start) * 1000

                    lock.lock()
                    totalTime += Int64(duration)
                    successCount += 1
                    lock.unlock()
                }
            }
            task.resume()
        }
    }

    group.notify(queue: DispatchQueue.main) {
        if successCount == 0 {
            completion(0, "Proxies Failed")
        } else {
            let averageTime = Int(Double(totalTime) / Double(successCount))
            completion(averageTime, "")
        }
    }
}

Delegate example

class ProxySessionDelegate: NSObject, URLSessionDelegate {
    let username: String
    let password: String

    init(username: String, password: String) {
        self.username = username
        self.password = password
    }

    func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodHTTPBasic {
            let credential = URLCredential(user: self.username, password: self.password, persistence: .forSession)
            completionHandler(.useCredential, credential)
        } else {
            completionHandler(.performDefaultHandling, nil)
        }
    }
}