WooCommerce - product-attribute.php for html attribute

<?php
// WooCommerce - product-attribute.php for html attribute
if( 'attribute_with html_name' == $product_attribute['label'] ) {
  $product_id = $product->get_id();
  $ats = get_post_meta( $product_id, '_product_attributes', true );
  foreach( $ats as $at ) {
    if( 'attribute_with html_name' == $at['name'] ) {
      $product_attribute['value'] = html_entity_decode( $at['value'], ENT_COMPAT | ENT_HTML5 );
    }
  }
}
?>