Button 'Reset Grid' works but doesn't appear

Can anyone help me why my “Reset Grid” doesn’t appear? He’s working

<div id="ajaxCrudDatatable">



        'dataProvider' => $dataProvider,

        'filterModel' => $searchModel,


        'columns' => require(__DIR__.'/_columns.php'),

        'toolbar'=> [


                Html::a(Yii::t('yii2-ajaxcrud', 'Create New'), ['create'],

                ['role'=>'modal-remote','title'=> Yii::t('yii2-ajaxcrud', 'Create New').' Estabelecimentos','class'=>'btn btn-outline-primary']).

                Html::a('<i class="fa fa-trash"></i>', [''],

                ['data-pjax'=>1, 'class'=>'btn btn-outline-success', 'title' => Yii::t('app', 'Reset Grid')]).





        'striped' => true,

        'condensed' => true,

        'responsive' => true,          

        'panel' => [

            'type' => 'default', 

            'heading' => '<i class="fa fa-list"></i> <b>'.$this->title.'</b>',

            'before'=>'<em>* '.Yii::t('yii2-ajaxcrud', 'Resize Column').'</em>',


                        'buttons'=>Html::a('<i class="fa fa-trash"></i>&nbsp; '.Yii::t('yii2-ajaxcrud', 'Delete All'),

                            ["bulkdelete"] ,


                                "class"=>"btn btn-danger btn-xs",


                                'data-confirm'=>false, 'data-method'=>false,// for overide yii data api


                                'data-confirm-title' => Yii::t('yii2-ajaxcrud', 'Delete'),

                                'data-confirm-message' => Yii::t('yii2-ajaxcrud', 'Delete Confirm')



                    '<div class="clearfix"></div>',




when i pass the mouse over i can see it


very difficult to understand. Please. explain in details to get meaningful help!