Why is the socket.io server not working?

Question

Node.js

I want to use Laravel in conjunction with socket.io (I use laradock).
Here is server.js code

let io = require('socket.io')(6001);

io.on('connect', function (socket) {
    console.log('hi');
});

Here is the client:

<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/1.4.5/socket.io.min.js"></script>
<script>
    let socket = io('http://localhost:6001')
</script>

The server through node is started. Here's what happens in the console on the client:

I tried to set other ports in both files and on the client options like:

let socket = io(':6001')
    let socket = io.connect('http://localhost:6001')
    let socket = io.connect(':6001')

Nothing helped. Googled, the solutions did not help.

Answer 1

Didn't approach the problem from the right direction. I tried without docker (I also have node.js installed locally) and everything works. Apparently the problem is still somewhere with laradock