Как реализовать ожидание завершения запроса с QNetworkAccessManager в Qt?

конструктор(){
      manager = new QNetworkAccessManager(this);
      connect(manager, SIGNAL(finished(QNetworkReply*)), SLOT(replyFinished(QNetworkReply*)));
    QObject::connect(manager, QOverload<QNetworkReply*>::of(&QNetworkAccessManager::finished),
                     &loop, &QEventLoop::quit);
  }

  void MainWindow::replyFinished(QNetworkReply* reply){
      if (reply->error() == QNetworkReply::NoError){
            if(needProxy){
                changeProxy();
                sendRequest();
                QTimer::singleShot(3000, &loop, &QEventLoop::quit);
            }
      }
      reply->deleteLater();
  }

  void MainWindow::onClicked(){
        sendFirstRequest();
        loop.exec():
  }

конструктор(){
    manager = new QNetworkAccessManager(this);
    connect(manager, SIGNAL(finished(QNetworkReply*)), SLOT(replyFinished(QNetworkReply*)));
    QObject::connect(manager, QOverload<QNetworkReply*>::of(&QNetworkAccessManager::finished),
                     &loop, &QEventLoop::quit);
}

  void MainWindow::replyFinished(QNetworkReply* reply){
      if (reply->error() == QNetworkReply::NoError){
            if(url.contains("test1")){
                sendRequest("test/main1");
                
            }else if(url.contains("test2")){
                sendRequest("test/main2");
                
            }else if(url.contains("test3")){
                sendRequest("test/main3");
                
            }else{
                sendRequest("test/default");
                changeProxy();
            }
      }
      reply->deleteLater();
  }

  void MainWindow::sendRequest(const QString& url){
        manager->get(QNetworkRequest(QUrl(url)));
        QTimer::singleShot(3000, &loop, &QEventLoop::quit);
        loop.exec();
  }

  void MainWindow::onClicked(){
        sendRequest("test/default");
  }