how to send data to the frontend using SEE(Server-Sent Events)?

Question

My code in the controller that generates the user template on which the data will be displayed looks like this:

exports.getDashboard = (req, res, next) => {
    userId = req.user._id;
    Stocks.find({ userId: userId })
        .then(stocks => {
            res.render('user/dashboard', {
                pageTitle: 'Dashboard',
                path: '/user/dashboard',
                stock: stock,
                userId: userId,
            });
        })
}

the code that receives this data to create the graph looks like this:

    const userId = '<%= userId %>';
    const eventSource = new EventSource('/user/dashboard/' + userId);

I don't know how to make sse send data to /user/dashboard/:userId. I have tried various methods but sse only works for me when I do not execute res.render only res to send and I want on this url to execute the sending of data but also want to have my view dashboard.ejs.