I wrote a simple server example in JavaScript that sends some data to a client when the client connects: send-gravity-from-server-to-client-box2d-wasm-js

I deployed this simple server on free hostings: https://glitch.com/ and https://render.com/. Web clients work well:

• Glitch: https://merciful-regal-soursop.glitch.me
• Render: https://send-gravity-box2d-wasm-js.onrender.com
  (It takes 15-20 seconds for Glitch and 50 seconds for Render to wake up the server)

I try to connect to the server from Qt and show received data:

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    connect(&m_webSocket, &QWebSocket::connected, this, &Widget::onConnected);
    connect(&m_webSocket, &QWebSocket::textMessageReceived,
            this, &Widget::onMessageReceived);
    // QUrl url("wss://send-gravity-box2d-wasm-js.onrender.com");
    QUrl url("wss://merciful-regal-soursop.glitch.me");
    m_webSocket.open(url);
}

Widget::~Widget() {}

void Widget::onConnected()
{
    qDebug() << "connected";
}

void Widget::onMessageReceived(const QString &message)
{
    qDebug() << message;
}

I see connected in the Qt Debug console when I try to connect to Render and I see nothing when I try to connect to Glitch.