code: public function actionCreate()
      {
          $model = new Item();
  
          if ($model->load(Yii::$app->request->post()) && $model->save()) {
              return $this->redirect(['index']);
          } else {
              return $this->render('create', [
                  'model' => $model,
              ]);
          }
      }
docs: Creates a new Item model.
  If creation is successful, the browser will be redirected to the 'view' page.
  @return mixed