Форум

$el_props = [
       'IBLOCK_ID' => get_iblock_id('requests2'),
       'IBLOCK_SECTION_ID' => get_iblock_section_id('requests2', 'career'),
         'NAME' => $params['name'] . ' | ' . $params['phone'],
       'ACTIVE' => 'Y',
        'DETAIL_TEXT' => $form_message,
       'PROPERTY_VALUES' => array(
        'RESUME_FILE' => [
            'n0' => [
                'VALUE' => CFile::MakeFileArray($this->files['file'])
            ]
        ]
    )
];

// Заявка с раздела /career/ [Основной сайт]
public static function create_career_request_ticket($params)
{
    try {

        # Валидация

        $validation = validation::validate([
            ['value' => $params['name'], 'required' => true, 'validator' => 'name',],
            ['value' => $params['phone'], 'required' => true, 'validator' => 'phone',],
            ['value' => $params['email'], 'required' => true, 'validator' => 'email',]            
        ]);

        if (count($validation['errors']))
            throw new Exception(implode(';', $validation['errors']));

        # Формирование сообщения

        $form_message = 'Новая заявка с формы "Вакансии';
        $form_message .= $params['FORM_NAME'] . '".' . PHP_EOL;
        $form_message .= PHP_EOL;
        $form_message .= 'Имя: ' . $params['name'] . PHP_EOL;
        $form_message .= 'Телефон: ' . $params['phone'] . PHP_EOL;
        $form_message .= 'Почта: ' . $params['email'] . PHP_EOL;
        $form_message .= 'Город: ' . $params['city'] . PHP_EOL;
        $form_message .= 'Информация о кандидате: ' . $params['comment'] . PHP_EOL;

        # Отправка почты

        if (!CEvent::Send("CAREER_FORM", "s2", ['MESSAGE' => $form_message]))
            throw new Exception('Ошибка в отправке сообщения, попробуйте ещё раз');


          // если есть вложение
            if (!empty($_FILES['file']['tmp_name'])) {

            // Закачиваем файл в /tmp_resume
            $name = $_FILES['file']['name'];
            $uploads_dir = $_SERVER['DOCUMENT_ROOT'].'/tmp_resume';
            $is_moved = move_uploaded_file($_FILES['file']['tmp_name'], "$uploads_dir/$name");

            }
        # Добавление элемента в инфоблок

        Loader::includeModule("iblock");
        $el = new CIBlockElement();

        $el_props = [
       'IBLOCK_ID' => get_iblock_id('requests2'),
       'IBLOCK_SECTION_ID' => get_iblock_section_id('requests2', 'career'),
         'NAME' => $params['name'] . ' | ' . $params['phone'],
       'ACTIVE' => 'Y',
        'DETAIL_TEXT' => $form_message,
       'PROPERTY_VALUES' => array(
        'RESUME_FILE' => [
            'n0' => [
                'VALUE' => CFile::MakeFileArray($_SERVER["DOCUMENT_ROOT"]."/tmp_resume/".$name)
            ]
        ]
    )
];
        if (!$el->Add($el_props))
            throw new Exception($el->LAST_ERROR);

        # Возврат удовлетворительного состояния

        return [
            'status' => 'success',
            'data' => [
                'message' => "Форма успешно отправлена"
            ]
        ];

    } catch (Exception $e) {

        return [
            'status' => 'error',
            'data' => [
                'errors' => explode(';', $e->getMessage()),
            ]
        ];

    }
}

<fo rm class="landing-header__form landing-form js-ajax-form" enctype="multipart/form-data">

<input type="file" class="landing-modal-form__field-input input input--primary js-ajax-form-input" name="file" placeholder="Ваше резюме">