Jquery on client side with nodejs server

I use nodejs (in a docker-compose container, not sure if that is relevant) to set up a local web app. I would like to use jquery on the client-side to load an HTML file into a div. Unfortunately, it is not working. The initial index.html and the new.html are in the same folder (/frontend/). What am I missing?

Nodejs app:


var app = express();

// home route returns rendered html content
app.get("/", (req, res) => {
  res.sendFile(__dirname + "/frontend/index.html");
});

app.listen(3000, function(){
    console.log('Example app listening on port 3000!');
});

index.html:

<!DOCTYPE html>
<html>
    <head>
        <script src="https://code.jquery.com/jquery-3.6.0.min.js"
            integrity="sha256-/xUj+3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4="
            crossorigin="anonymous">
        </script>
        
        <script type="text/javascript">
            $(document).ready(function(){
                $("#imported").load("new.html");
            });
        </script>
    </head>
    <body>
        <div> This is content of the index HTML and below is the imported HTML:</div>
        
        <div id="imported"></div>
    </body>
</html>

Lastly the HTML I want to import new.html:

<HTML>
  <head>
  </head>
  <body>
    <p>This is demo text.<p>
  </body>
</html>