Why is there an error in the nav widget?

Question

Yii

I tried to automatically add items to the menu when adding entries to the firmcat table in the nav widget like this

if(isset($firm)){
                            function menuitemFirm($firm){

                                $arr=array();
                                foreach($firm as $cat){
                                    array_push($arr,[
                                            'label'=>Html::tag('span',Html::img(iconFirm($cat->id)),['class'=>'col-md-8 noMobile']).''. Html::tag('span',$cat->title,['class'=>'col-md-16 col-sm-12 col-xs-24']),
                                            'url'=>['/firmcat/list?id='.$cat->id],
                                            'linkOptions'=>[
                                                'class' => $cat->id.' col-md-24 col-xs-24'
                                                ],

                                            'encode' => false
                                            ]);
                                }
                                return $arr;
                            }

                            $menuItems[]=[
                                'label' => 'По производителям',
                                'url' =>'#',
                                'items' => [ menuitemFirm($firm)],
                                'dropDownOptions'=>[
                                        'class'=>'dropdown-menu col-md-24 col-xs-24'

                                ],
                            ];
                        }

where $firm is $firm=Firmcat::find()->all(); got the error The 'label' option is required. Firmcat has two entries, if I write var_dump($arr) I'll get

array(2) {
 [0]=> array(4) { 
  ["label"]=> string(212) "Алуштинский эфиромасличный совхоз-завод" 
  ["url"]=> array(1) { [0]=> string(18) "/firmcat/list?id=1" }
  ["linkOptions"]=> array(1) { 
    ["class"]=> string(21) "1 col-md-24 col-xs-24" } 
  ["encode"]=> bool(false) } 
[1]=> array(4) { 
  ["label"]=> string(166) "Крымская стевия" 
  ["url"]=> array(1) { 
  [0]=> string(18) "/firmcat/list?id=2" }
  ["linkOptions"]=> array(1) { 
    ["class"]=> string(21) "2 col-md-24 col-xs-24" 
  } 
  ["encode"]=> bool(false) } }

why does this error occur?