just incompatibility or real error in swift code - swift

Question

hello i am working with swift 6.2 ( the performance of my pc doesn't support ++)
i have copied from open classroom this program in my file but there are many errors
i just want to know if it is just problem of swift compatibility or there are really errors in the code
//****************
import UIKit
class QuestionManager {
private let url = URL(string: "https://opentdb.com/api.php?amount=10&type=boolean")!
// exemple of message error: use of unresolved identifier 'URL'
static let shared = QuestionManager()
private init() {}
// FIX IT : replace static with class ...
// AND LOT OF MESSAGE ERROR LIKE THIS...
func get(completionHandler: #escaping ([Question]) -> ()) {
let task = URLSession.shared.dataTask(with: self.url) { (data, response, error) in
guard error == nil else {
completionHandler([Question]())
return
}
DispatchQueue.main.async {
completionHandler(self.parse(data: data))
}
}
task.resume()
}
private func parse(data: Data?) -> [Question] {
guard let data = data,
let serializedJson = try? JSONSerialization.jsonObject(with: data, options: []),
let parsedJson = serializedJson as? [String: Any],
let results = parsedJson["results"] as? [[String: Any]] else {
return [Question]()
}
return getQuestionsFrom(parsedDatas: results)
}
private func getQuestionsFrom(parsedDatas: [[String: Any]]) -> [Question]{
var retrievedQuestions = [Question]()
for parsedData in parsedDatas {
retrievedQuestions.append(getQuestionFrom(parsedData: parsedData))
}
return retrievedQuestions
}
private func getQuestionFrom(parsedData: [String: Any]) -> Question {
if let title = parsedData["question"] as? String,
let answer = parsedData["correct_answer"] as? String {
return Question(title: String(htmlEncodedString: title)!, isCorrect: (answer == "True"))
}
return Question()
}
}
extension String {
init?(htmlEncodedString: String) {
guard let data = htmlEncodedString.data(using: .utf8) else {
return nil
}
let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html,
NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue
]
guard let attributedString = try? NSAttributedString(data: data, options: options, documentAttributes: nil) else {
return nil
}
self.init(attributedString.string)
}
}