Error: Class "Websocket\Client" not found

I feel like this should not be so difficult, but I'm struggling with it for almost the entire day, so I'm asking for help!

I installed a websocket client with composer like this: 

Code:

composer require textalk/websocket

I use IntelliJ, and when I add

PHP Code:

use Websocket\Client; 


 and then initiate a connection with

PHP Code:

$wsClient = new Client($URL);  


there are no IDE errors indicated regarding any missing dependencies.  However, when I run the code, I get an error Class "Websocket\Client" not found.  

I have located all of the needed files in vendor/textalk folder, checked all autoload files exist, but I just don't know where to go from here. 
Thanks in advance!!!

Refresh IDE. 
I install package in demo. It work. 

PHP Code:

<?php

declare(strict_types=1);

namespace App\Controllers;

use WebSocket\Client;

class Home extends BaseController
{
    public function index()
    {
        $wsClient = new Client('ws://site.com/');
        dd($wsClient);
    }
} 


Code:

$wsClient WebSocket\Client#94 (6)
Properties (6)Available methods (23)Static class properties (2)
⧉protected logger -> Psr\Log\NullLogger#97 (0)
private connection -> null
private last_opcode -> null
private listen -> boolean false
⧉private options -> array (9)
⧉private socket_uri -> Phrity\Net\Uri#95 (9)
⧉Called from .../app/Controllers/Home.php:23 [dd()]

Simple CI 4 project for beginners codeigniter-expenses ( topic )

Because you typed the classname.
It is "WebSocket\Client" not "Websocket\Client".

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

Because you typed the classname.
It is "WebSocket\Client" not "Websocket\Client".

Well you're a lifesaver.  And I feel stupid!! Thank you!!!