PHPUnit testing dynamically created form elements

I am writing phpunit tests for a form. In my form, I dynamically created array input elements with jquery. However, I cannot find a way to recreate these elements in jquery. I am consistently getting InvalidArgumentException: Unreachable field "", because my form does not contain these elements (till jquery creates them).

I am using Laravel 5.3. Any suggestions?

Dynamically created element:

<fieldset class="package">
  <div class="form-group" style="padding-bottom: 30px;">
    <section>
    <label class="label control-label col-md-1" style="padding-top: 7px;">Pallet</label>
      <div class="col-md-11"><label class="input">
      <div class="input-group">          
      <input value="1234" type="text" name="package_barcode[]" text="1234">
      <input value="Pallet" type="hidden" name="package_type[]">
      <div class="input-group- btn"> <button class="btn-inline btn-danger remove_package" type="button">Cancel Package </button> </div>
      </div>
      </label>  
      </div>
    </section>
  </div>
</fieldset>

via kingpanic