Why is the Yii2 validator not working?

Question

Yii

Model: Setting

<?php

namespace app\modules\panel\models;

use app\models\User;
use Yii;
use yii\base\Model;

/**
 * Login the model behind the login form.
 */
class Setting extends Model
{
    public $login;
    public $name;
    public $vk;
    public $password;
    public $passwordTwo;

    public function rules()
    {
        return [
            [['login', 'name', 'vk'], 'string'],
            ['password', 'validatePassword'],
        ];
    }
    public function validatePassword($attribute, $params)
    {
        $this->addError($attribute, 'сразу ошибка без проверок');
    }
    
}

Action in controller:

public function actionSetting()
    {
        if (Yii::$app->request->isPost) {
            $model = new Setting();
            $model->load(Yii::$app->request->post());
            $model->updateUser();
        }
        $dbUser = User::findOne(Yii::$app->user->identity->id);
        $user = new Setting();
        $user->login = $dbUser->login;
        $user->name = $dbUser->name;
        $user->vk = $dbUser->vk;

        return $this->render('setting', compact('user'));
    }

Just for the sake of verification, I installed a built-in validator:

['passwordTwo', 'compare', 'compareAttribute' => 'password']

He works. But the custom one does not work ... It does not give anything at all. Not green nor red stroke:

Answer 1

This $this->addError($attribute, 'immediate error without checks') will only work if the form is validated on the server. For dynamic validation, look for information in the docks.