public function actionCreateAjax()
 {
     $model = new Callback();
     $module = Module::getInstance();
     $model->load(\Yii::$app->request->post());
     $model->createdAt = Date('Y-m-d H:i:s');
     if ($model->save()) {
         if ($module->email) {
             Yii::$app->mailer->compose($module->mailTemplate, ['model' => $model])->setFrom($module->email)->setTo($module->email)->setSubject($module->subject)->send();
         }
         return json_encode(true);
     }
     return json_encode($model->getErrors());
 }