I'm opening index.html with the Live Server extension for VS code, so I know it's hosting on http://127.0.0.1:5500.

When I try to run a server.js file on 5500, like that:

const app = express();
app.listen(5500, () => console.log('listening on 5500...'));

it gives the

Error: listen EADDRINUSE: address already in use :::5500

how can I host them both in the same place or alternatively, if I choose to host the server on port 3000, how can I set up the html code so it goes to the right place?

<form action = "/frases" method="post">
            <input id= 'frase' type="text" name="frasefavorita">
            <button id= 'send-frase' type="submit">Enviar</button>
    </form>