code: public function actionRequest()
      {
          if (!$this->module->enablePasswordRecovery) {
              throw new NotFoundHttpException;
          }
  
          $model = \Yii::createObject([
              'class'    => RecoveryForm::className(),
              'scenario' => 'request',
          ]);
  
          $this->performAjaxValidation($model);
  
          if ($model->load(\Yii::$app->request->post()) && $model->sendRecoveryMessage()) {
              return $this->render('/message', [
                  'title'  => \Yii::t('user', 'Recovery message sent'),
                  'module' => $this->module,
              ]);
          }
  
          return $this->render('request', [
              'model' => $model,
          ]);
      }
docs: Shows page where user can request password recovery.
  @return string
  @throws \yii\web\NotFoundHttpException