Why does this error occur(Pjax)?

Question

Yii

Trying to load ActiveForm via pjax

<? \yii\widgets\Pjax::begin()?>
<div class="client-index">

    <h3><?= Html::encode($this->title) ?></h3>
    <p>
        <?= Html::a(Yii::t('app', 'Create client'), ['create'], ['class' => 'btn btn-success', 'id' => 'create_client']) ?>
    </p>
    <?= ListView::widget([
    'dataProvider' => $dataProvider,
    'options' => [
        'tag' => 'div',
        'class' => 'list-wrapper',
        'id' => 'list-wrapper',
        ],
    'layout' => "{summary}\n{pager}\n{items}",
    'itemView' => function ($model, $key, $index, $widget) {
        return Html::a($model->name, ['/client/view'.'?id='.$model->id], ['class'=>'btn btn-default']);
        //return Html::a('button', $model->name, ['type' => 'button', 'class' => 'btn btn-sm btn-default', 'id' => $model->id]);
    }
    ]);
    ?>
</div>
<? \yii\widgets\Pjax::end() ?>

Controller:

public function actionCreate()
    {
        $model = new Client();
        $model->user_id = Yii::$app->user->identity->getId();
        if (Yii::$app->request->isAjax)
        {
            return $this->renderAjax('create', [
                'model' => $model,
            ]);
        }

after loading the page, the message Uncaught TypeError appears in the console
: jQuery (...). yiiActiveForm is not a function
Naturally, the form does not work. What could be causing this and what needs to be done?

Answer 1

I solved the problem by connecting js files explicitly, they were not loaded when requested ... or they were loaded incorrectly.

Answer 2

Trying to load ActiveForm

Where?