code: public function actionLogin()
      {
          $model = \Yii::createObject(LoginForm::className());
  
          $this->performAjaxValidation($model);
  
          if ($model->load(\Yii::$app->getRequest()->post()) && $model->login()) {
              return $this->goBack();
          }
  
          return $this->render('login', [
              'model'  => $model,
              'module' => $this->module,
          ]);
      }
docs: Displays the login page.
  @return string|\yii\web\Response