How i can change the value of the checkbox base in a dropDownList dinamically

I have a form and a need to change the checkbox to checked or unchecked based int selection of the dropDownList. I am a begner in PHP and Yii2 here my form

<div class="npi-approval-review-form">

<?php if(!empty(Yii::$app->session->get('activity') && Yii::$app->session->get('activity')->need_signature == 'S'))$model->sign = 1; ?><?php ?>

    <?php $form = ActiveForm::begin(); ?>
        <table>
            <tbody>

            <tr>
                <td>
                    <?php if ($model->type == TypeOrigin::Aprovação): ?>
                    <?= $form->field($model, 'status')->dropDownList(StatusReview::asArray(), ['prompt'=>StatusApproval::asArray()[$model->status]]); ?>
                    <?php endif; ?>

                    <?php if ($model->type == TypeOrigin::Revisão): ?>
                        <?= $form->field($model, 'status')->dropDownList(StatusReview::asArray(), ['prompt'=>StatusReview::asArray()[$model->status]]); ?>
                    <?php endif; ?>
                </td>

                <td>&nbsp;&nbsp;&nbsp;</td>

                <td>
                    <?= $form->field($model, 'type')->textInput(['value'=>TypeOrigin::asArray()[$model->type]
                    , 'readonly' => true, 'disabled' => 'true']);?>
                </td>
            </tr>
            </tbody>
        </table>

        <?= $form->field($model, 'conclusion')->textarea(['rows' => 5, 'maxlength' => true]) ?>

        <?= $form->field($model, 'sign')->checkBox(['value'=> $model->status == '2' ? '0' : '1']) ?>

        <div class="form-group">
            <?= Html::submitButton('Salvar', ['class' => 'btn btn-success']) ?>
        </div>

    <?php ActiveForm::end(); ?>

</div>