How to display field “VAT Number” (required) during registration.

This field is visible when editing the user from the administration panel. Only how to display them during registration?

I found code in:

app/design/frontend/{YOUR_PACKAGE}/{YOUR_THEME}/Magento_Customer/templates/form/register.phtml 

This file contains fields that are displayed during registration:

            <input type="hidden" name="create_address" value="1" />         <div class="field company">             <label for="company" class="label"><span><?php /* @escapeNotVerified */ echo __('Company') ?></span></label>             <div class="control">                 <input type="text" name="company" id="company" value="<?php echo $  block->escapeHtml($  block->getFormData()->getCompany()) ?>" title="<?php /* @escapeNotVerified */ echo __('Company') ?>" class="input-text <?php /* @escapeNotVerified */ echo $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('company') ?>">             </div>         </div>         <div class="field telephone">             <label for="telephone" class="label"><span><?php /* @escapeNotVerified */ echo __('Phone Number') ?></span></label>             <div class="control">                 <input type="text" name="telephone" id="telephone" value="<?php echo $  block->escapeHtml($  block->getFormData()->getTelephone()) ?>" title="<?php /* @escapeNotVerified */ echo __('Phone Number') ?>" class="input-text <?php /* @escapeNotVerified */ echo $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('telephone') ?>">             </div>         </div>          <?php $  _streetValidationClass = $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('street'); ?>          <div class="field street required">             <label for="street_1" class="label"><span><?php /* @escapeNotVerified */ echo __('Street Address') ?></span></label>             <div class="control">                 <input type="text" name="street[]" value="<?php echo $  block->escapeHtml($  block->getFormData()->getStreet(0)) ?>" title="<?php /* @escapeNotVerified */ echo __('Street Address') ?>" id="street_1" class="input-text <?php /* @escapeNotVerified */ echo $  _streetValidationClass ?>">                 <div class="nested">                     <?php $  _streetValidationClass = trim(str_replace('required-entry', '', $  _streetValidationClass)); ?>                     <?php for ($  _i = 2, $  _n = $  this->helper('Magento\Customer\Helper\Address')->getStreetLines(); $  _i <= $  _n; $  _i++): ?>                         <div class="field additional">                             <label class="label" for="street_<?php /* @escapeNotVerified */ echo $  _i ?>">                                 <span><?php /* @escapeNotVerified */ echo __('Address') ?></span>                             </label>                             <div class="control">                                 <input type="text" name="street[]" value="<?php echo $  block->escapeHtml($  block->getFormData()->getStreetLine($  _i - 1)) ?>" title="<?php /* @escapeNotVerified */ echo __('Street Address %1', $  _i) ?>" id="street_<?php /* @escapeNotVerified */ echo $  _i ?>" class="input-text <?php /* @escapeNotVerified */ echo $  _streetValidationClass ?>">                             </div>                         </div>                     <?php endfor; ?>                 </div>             </div>         </div>          <div class="field required">             <label for="city" class="label"><span><?php /* @escapeNotVerified */ echo __('City') ?></span></label>             <div class="control">                 <input type="text" name="city" value="<?php echo $  block->escapeHtml($  block->getFormData()->getCity()) ?>" title="<?php /* @escapeNotVerified */ echo __('City') ?>" class="input-text <?php /* @escapeNotVerified */ echo $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('city') ?>" id="city">             </div>         </div>          <div class="field region required">             <label for="region_id" class="label"><span><?php /* @escapeNotVerified */ echo __('State/Province') ?></span></label>             <div class="control">                 <select id="region_id" name="region_id" title="<?php /* @escapeNotVerified */ echo __('State/Province') ?>" class="validate-select" style="display:none;">                     <option value=""><?php /* @escapeNotVerified */ echo __('Please select a region, state or province.') ?></option>                 </select>                 <input type="text" id="region" name="region" value="<?php echo $  block->escapeHtml($  block->getRegion()) ?>" title="<?php /* @escapeNotVerified */ echo __('State/Province') ?>" class="input-text <?php /* @escapeNotVerified */ echo $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('region') ?>" style="display:none;">             </div>         </div>          <div class="field zip required">             <label for="zip" class="label"><span><?php /* @escapeNotVerified */ echo __('Zip/Postal Code') ?></span></label>             <div class="control">                 <input type="text" name="postcode" value="<?php echo $  block->escapeHtml($  block->getFormData()->getPostcode()) ?>" title="<?php /* @escapeNotVerified */ echo __('Zip/Postal Code') ?>" id="zip" class="input-text validate-zip-international <?php /* @escapeNotVerified */ echo $  this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('postcode') ?>">             </div>         </div>          <div class="field country required">             <label for="country" class="label"><span><?php /* @escapeNotVerified */ echo __('Country') ?></span></label>             <div class="control">                 <?php echo $  block->getCountryHtmlSelect() ?>             </div>         </div>         <?php $  addressAttributes = $  block->getChildBlock('customer_form_address_user_attributes');?>         <?php if ($  addressAttributes): ?>             <?php $  addressAttributes->setEntityType('customer_address'); ?>             <?php $  addressAttributes->setFieldIdFormat('address:%1$  s')->setFieldNameFormat('address[%1$  s]');?>             <?php $  block->restoreSessionData($  addressAttributes->getMetadataForm(), 'address');?>             <?php echo $  addressAttributes->setShowContainer(false)->toHtml()?>         <?php endif;?>         <input type="hidden" name="default_billing" value="1">         <input type="hidden" name="default_shipping" value="1">     </fieldset> 

I also found this code in this file:

<?php $  _taxvat = $  block->getLayout()->createBlock('Magento\Customer\Block\Widget\Taxvat') ?>     <?php if ($  _taxvat->isEnabled()): ?>         <?php echo $  _taxvat->setTaxvat($  block->getFormData()->getTaxvat())->toHtml() ?>     <<?php endif ?>