Administrator / test_1

  <?php
  use yii\widgets\ActiveForm;
  ?>
  
  <?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]) ?>
  
  <?= $form->field($model, 'file')->fileInput() ?>
  

  <button>Прочитать</button>

  
  <?php ActiveForm::end() ?>