How can I deploy SvelteKit IO app with two ports?

I'm using the SvelteKit IO library for sockets in my SvelteKit application.

My main application, when built, runs on port 4173. My socket runs on 3001.

Here's the SKIO setup code: I can't change 3001 to 4173 without encountering an error.

skio.setup('http://localhost:3001', {    cors: {        origin: "http://localhost:4173",        credentials: true,    },}).then(io => {    if (browser)        return;    io.on('connect', socket => {        socket.on('message', (message) => {            if (message.game_stop === true) {                socket.disconnect()            } else {                socket.emit('message', message);                socket.broadcast.emit('message', message);            }        });    });});

How do I deploy such an app with two ports?