Как настроить свой signup в yii2?

if ($this->validate()) {
            return
                Yii::$app->user->login(
                    $this->getUser(),
                    $this->rememberMe ? 3600 * 24 * 30 : 0
                );
        }
        return false;


public function getUser()
    {
        if ($this->_user === null) {
            $this->_user = User::findByUsername($this->username);
        }
        return $this->_user;
    }