How to set dark mode on QWebEngineView?

Question

I tried all options found here: 1, 2, 3

but dark theme still not being applied.

Testing on Qt 6.4 and Windows 10.

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);


    // qputenv("QTWEBENGINE_CHROMIUM_FLAGS",
    //      "--blink-settings=darkMode=4,darkModeImagePolicy=2");
    // qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--force-dark-mode");
    
    //qputenv("QTWEBENGINE_CHROMIUM_FLAGS",
    //    "--blink-settings=darkModeEnabled=true,--blink-settings=darkMode=4,darkModeImagePolicy=2,--force-dark-mode,--blink-settings=forceDarkModeEnabled=true,darkmodeenabled=true");


    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "blink-settings=darkMode=4,darkModeImagePolicy=0");

    auto web = new QWebEngineView(this);
    web->setUrl(QUrl("https://www.google.com/"));
}