Why is Select2 kartik not showing input fields and hidden?

Question

Yii

Good afternoon!
I connected the Select2 plugin from kartik and as a result there is no form for selection.

<?php


use kartik\select2\Select2;
use yii\helpers\Html;
use yii\widgets\ActiveForm;

$form = ActiveForm::begin(); ?>

var_dump($data);

echo $form->field($model, 'subscriber')->widget(Select2::classname(), [
    'data' => $data,
    'options' => [
    	'placeholder' => 'Select a state ...'
    ],
    'pluginOptions' => [
        'allowClear' => true
    ],
]);

ActiveForm::end(); 

?>

As a result, we get the following result:

<form id="w0" action="/appeal/create" method="post">
<input type="hidden" name="_csrf" value="sAiGBmoczOEC3d_0ltMF0oiQ-CajulQCw5yJFOvXld3SX8JWBiu41U2NuoTD6miX6efNEMLvDVqLsc5ApbXZrA==">array(4) {
  [1]=&gt;
  string(1) "1"
  [2]=&gt;
  string(1) "2"
  [3]=&gt;
  string(1) "3"
  [4]=&gt;
  string(1) "4"
}
<div class="form-group field-appealform-subscriber">
<label class="control-label" for="appealform-subscriber">Subscriber</label>
<select id="appealform-subscriber" class="form-control select2-hidden-accessible" name="AppealForm[subscriber]" data-s2-options="s2options_d6851687" data-krajee-select2="select2_9f933b6f" style="width: 1px; height: 1px; visibility: hidden;" data-select2-id="select2-data-appealform-subscriber" tabindex="-1" aria-hidden="true">
<option value="" data-select2-id="select2-data-2-gica">Select a state ...</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select><span class="select2 select2-container select2-container--krajee" dir="ltr" data-select2-id="select2-data-1-otl2" style="width: 100%;"><span class="selection"><span class="select2-selection select2-selection--single" role="combobox" aria-haspopup="true" aria-expanded="false" tabindex="0" aria-disabled="false" aria-labelledby="select2-appealform-subscriber-container"><span class="select2-selection__rendered" id="select2-appealform-subscriber-container" role="textbox" aria-readonly="true"><span class="select2-selection__placeholder">Select a state ...</span></span><span class="select2-selection__arrow" role="presentation"><b role="presentation"></b></span></span></span><span class="dropdown-wrapper" aria-hidden="true"></span></span>

<div class="help-block"></div>
</div></form>

It can be seen that everything is being formed, but there is no Select2 field itself.
What could be the problem?