Yii2 widget date picker on date selection

In order to trigger a function on date selection on Kartik date picker we need to assign it in pluginevents.

echo $form->field($model, 'OrderDate')
->widget(DatePicker::classname(), [ 
        'options' => [ 
                       //'value' => Yii::$app->formatter->asDate($startDate, 'dd-m-yyyy') 
                      ],
         'type' => DatePicker::TYPE_INPUT,
       // 'onChangeDate' =>new \yii\web\JsExpression("function(dateText, inst) 
               {
                alert('hi');
               }"),
          //'disabled' => true,
        'pluginOptions' => [ 
                      'startDate' => (string) $startDate,
                      'autoclose' => true, 
                      'format' => 'dd-M-yyyy',           
                      'todayHighlight' => true,          
                       "endDate" => (string) date('d/m/Y', time() + (1 * 24 * 60 * 60)),
                           ],
          'pluginEvents' => [   
                        "change" => 'function()
                               {
                                var data_id = $(this).val();
                                $.ajax({
                                       type: "GET",
                                       url: "'.\yii\helpers\Url::to(['orders/fetchslots']).'",
                                       data: { dt: data_id },
                                       success: function(data) 
                                              {$("#orders-orderdeliveryslotid").html( data );
                                         },
                                  });}',  
                              ],
                             ])->label(false)  ;