Error websocket with catapult and typescript / angular

I am receiving 404 error, I am trying to connect to a Webservice in Typescript, the webservice is catapult, when opening the connection the output is http and not ws, even though in my url parameter I place ws: // mi- ip.

import { Listener, BlockInfo } from "nem2-sdk/dist";
const listener = new Listener('ws://miIp:3000');
listener.open();

When doing what I did above, the output in the browser is as follows:

GET http://miIp:3000/ws 404 (Not Found)

Fetch API cannot load http://miIp:3000/ws. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:4200' is therefore not allowed access. The response had HTTP status code 404. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

HELP PLEASE !!

This is the example that I am doing link