PHPUnit tests errors

Hi PLEASE SOMEONE CAN HELP ME,I'm noob in testing and I ran a test using PHPunit test and I got this error message

Error: Class 'App\Pages' not found //Summary of non-successful tests: Error: Class 'App\Pages' not found C:\xampp\htdocs\apptest\tests\PagesTest.php:8

Directory structure :

/apptest
    |app
      Pages.php
    |tests
      PagesTest.php
    |vendor
composer.json
composer.lock
index.php(bootstrap file)
    

Composer.json Config:

{
    "require": {
         "phpunit/phpunit": "^8.5"
    },
   "autoload":{
        "psr-4": {
          "App\\":"app/"
    }
}
    

Pages.php file code:

<?php
namespace App;
class Pages{
    public function getPage($id){
        return 'Hello';
    }
}
    

PagesTest.php code:

<?php
use PHPUnit\Framework\TestCase;

class PagesTest extends TestCase{
    
    protected $pages;
    protected function setUp():void{
        $this->pages = new App\Pages();
    }
    /**
     * @test
     */
    public function homePageReturnHello(){
        $excepted = 'Hello';
        $actual = $pages->getPage('1');
        $this->assertEquals($excepted, $actual);
    }
}