WebSocket Server configuration with Ionic 5

I'm trying to configure the WebSocket Server for my chat application. But the first thing that I faced is the error when I tried to run my project:

Uncaught Error: Type WebSocketServer does not have 'ɵmod' property.
    at getNgModuleDef (core.js:1022)
    at recurse (core.js:24986)
    at recurse (core.js:24997)
    at registerNgModuleType (core.js:24982)
    at new NgModuleFactory$1 (core.js:25096)
    at compileNgModuleFactory__POST_R3__ (core.js:28699)
    at PlatformRef.bootstrapModule (core.js:28942)
    at Module.zUnb (main.ts:11)
    at __webpack_require__ (bootstrap:84)
    at Object.0 (main.js:11)

In my app.module.ts file I import my socket server import { WebSocketServer } from '@ionic-native/web-socket-server/ngx';. After I resolve this issue I'm wondering how can I configure the WebSocket object that is shown in the documentation here:

import { WebSocketServer } from '@ionic-native/web-socket-server';

constructor(private wsserver: WebSocketServer) { }

...

// start websocket server
this.wsserver.start(8888, {}).subscribe({
  next: server => console.log(`Listening on ${server.addr}:${server.port}`),
  error: error => console.log(`Unexpected error`, error);
});

// watch for any messages
this.wsserver.watchMessage().subscribe(result => {
  console.log(`Received message ${result.msg} from ${result.conn.uuid}`);
});

// send message to connection with specified uuid
this.wsserver.send({ uuid: '8e7c4f48-de68-4b6f-8fca-1067a353968d' }, 'Hello World');

// stop websocket server
this.wsserver.stop().then(server => {
  console.log(`Stop listening on ${server.addr}:${server.port}`);
});

Helps are appreciated, thanks!