How to Redirect within a POST request in node js

Question

I am trying to redirect inside of the following method:

app.post('/api/generateAccount/', async (req, res) => 
{
// other stuff here
    res.redirect(`/404.html`); //just for testing
});

using the following fetch request:

 fetch('/api/generateAccount',
                        {
                            method: 'POST',
                        });

using nodemon I have the following printed: GET /404.html 304 - - 0.487 ms

but unfortunately the web page never changes within the browser, what would be the fix for this?