Why is the Class 'sergalas\header\Menus' not found error thrown?

Question

Yii

I'm trying to write my own widget that I would like to place in the vendor/sergalas/header folder here is the code

<?php
namespace sergalas\header;

use yii\base\Widget;
use common\models\Category;
use yii\helpers\ArrayHelper;
class Menus extends Widget{
    public $menu;
    public function init()
    {
        parent::init();
        $cat=Category::find()->where('tags=0')->all();
        $this->menu=ArrayHelper::toArray($cat,[
            'common\models\Category' => [
                'id',
                'name_category',

            ],
        ]);
    }

    public function run()
    {
        return 'Hello';
    }
}

Please explain where and what the error is and how to fix it. Or at least where to look for the answer?

Answer 1

in principle, the issue has already been resolved. I just didn't know if it's advisable to use a separate widgets folder.

Answer 2

Is the dependency on your package with autoload written in the composer?