Why does Minishop2 ms2Form not print size?

Question

MODX

Hello!
I have Minishop2 and ms2Form.
With this form, it outputs everything except size.
I don’t understand where the error is (
Did I insert name="options[size]" and value correctly?
Value is inserted via js
Here

In the admin panel, the product size is empty

Form

<form class="well create" method="post" action="" id="ms2form" role="form" data-reset="true">
  <input type="hidden" id="ms2formFormKey" name="form_key" value="">
  <input type="hidden" name="pid" value="0">
  <input type="hidden" name="parent" value="">
  <input type="hidden" name="published" value="1"/>
  <input type="hidden" name="hidemenu" value="0"/>
  <input type="hidden" name="redirectPublished" value=""/>
  <input type="hidden" id="ms2formTagsNew" value=""/>
  <div class="form-group">
    <label>ms2form_categories</label>
    <br/>
    <input type="hidden" class="form-control" id="ms2formSections">
  </div>
  <div class="input-group mb-3">
    <div class="input-group-prepend">
      <span class="input-group-text px-4" id="basic-addon1">25</span>
    </div>
    <input type="text" class="form-control" id="ms2formPagetitle" name="pagetitle" value="" placeholder="ms2form_pagetitle *" aria-label="Заголовок" aria-describedby="basic-addon1">
  </div>
  <div class="input-group mb-3">
  <input type="text" id="input" class="form-control" placeholder="Введите размера..." aria-label="Введите размера" aria-describedby="basic-addon2">
  <div class="input-group-append">
    <button id="button" class="btn btn-outline-secondary" type="button">Добавить размер</button>
  </div>
  </div>
  <div class="form-group">
    <label for="exampleFormControlSelect2">Размеры</label>
    <select multiple name="options[size]" class="form-control hidden" id="FormControlSelectSize">
    </select>
  </div>
  <div class="input-group mb-4">
    <input id="content" name="content" type="hidden" value="">
    
  </div>
  <div class="form-group">
    <h4>Добавить изображение</h4>
    <small id="emailHelp" class="form-text text-muted">Макс. размер 4048 КБ для каждого изображения</small>
  <div class="input-group mb-3">
    <div class="ticket-form-files w-100">
      
    </div>
  </div>
  </div>
  <div class="form-group">
    <input type="text" name="price" value="" class="form-control" id="priceInput" aria-describedby="price" placeholder="Цена*">
  </div>
  <div class="form-group my-4">
    <small id="emailHelp" class="form-text text-left text-muted h5">* Обязательные поля</small>
  </div>
  <div class="w-100 text-center">
    <input type="submit" value="ms2form_save" id="ms2formSubmit" class="btn btn-danger px-5 text-uppercase submit">
  </div>
  <div class="form-group">
    <small id="emailHelp" class="form-text text-muted text-left mt-3"><i class="fas fa-info-circle mr-2"></i>Нажимая на кнопку «Опубликовать», я даю согласие на обработку персональных данных»</small>
  </div>
</form>

Displaying a form in a template

Where is the output error?