Qt6: How to solve the qt.networkauth.oauth2: Unexpected call error on oAuth

[chilarai]

I have a code to connect to Google drive using QT6 but I keep getting the error qt.networkauth.replyhandler: Error transferring https://oauth2.googleapis.com/token - server replied: qt.networkauth.oauth2: Unexpected call

I have even implemented the suggested changes mentioned here https://stackoverflow.com/questions/63305525/cant-get-oauth-2-0-code-in-qt-app-but-is-seems-to-work-in-browser. This seem to have changed the encoding of code as expected but the end result is the same. I keep getting the same error. What am I missing?

My redirect url is http://127.0.0.1:5476

Google::GoogleCon(QObject *parent) : QObject(parent),
    m_networkAccessManager(new QNetworkAccessManager(this)),
    m_networkReply(nullptr),
    m_dataBuffer(new QByteArray)
{

    this->google = new QOAuth2AuthorizationCodeFlow(this);

    this->google->setScope("email https://www.googleapis.com/auth/drive");
    connect(this->google, &QOAuth2AuthorizationCodeFlow::authorizeWithBrowser, &QDesktopServices::openUrl);

    this->google->setAuthorizationUrl(QUrl("https://accounts.google.com/o/oauth2/auth"));
    this->google->setClientIdentifier(<CLIENT>);
    this->google->setAccessTokenUrl(QUrl("https://oauth2.googleapis.com/token"));
    this->google->setClientIdentifierSharedKey(<SECRET>);


    this->google->setModifyParametersFunction([this](QAbstractOAuth::Stage stage, QMultiMap<QString, QVariant>* parameters)
    {
        qDebug() << "modifyParametersFunction stage=" << static_cast<int>(stage);
        if (stage == QAbstractOAuth::Stage::RequestingAuthorization)
        {
            parameters->insert("access_type", "offline");
            parameters->insert("prompt", "consent");
        }
        else if (stage == QAbstractOAuth::Stage::RequestingAccessToken)
        {
            QByteArray code = parameters->value("code").toByteArray();
            QString codeString = QUrl::fromPercentEncoding(code);


            parameters->replace("code", codeString);

        }
    });

    auto replyHandler = new QOAuthHttpServerReplyHandler(5476, this);
    this->google->setReplyHandler(replyHandler);

    connect(this->google, &QOAuth2AuthorizationCodeFlow::granted, [=]() {
        qDebug() << "Access Granted!";
    });
}