i would like to add "Rating" structured data to my item.php

But i just have "votingPercentage" and "numOfvotes" to extend.

Does anyone have added structured data to the rating?

solved it with a 3rd party extension

Hello. I did it 3 or 4 years ago. If you need - i write here part of code, where you can see all fragments of code you need.

<div class="itemRatingBlock" itemprop="aggregateRating" itemscope="" itemtype="schema.org/AggregateRating">
<span></span>
<div class="itemRatingForm">
<ul class="itemRatingList">
<li class="itemCurrentRating" id="itemCurrentRating16441" style="width:0%;"></li>
<meta itemprop="ratingValue" content="0">
<li><a href="#" data-id="16441" title="1 star out of 5" class="one-star">1</a></li>
<li><a href="#" data-id="16441" title="2 stars out of 5" class="two-stars">2</a></li>
<li><a href="#" data-id="16441" title="3 stars out of 5" class="three-stars">3</a></li>
<li><a href="#" data-id="16441" title="4 stars out of 5" class="four-stars">4</a></li>
<li><a href="#" data-id="16441" title="5 stars out of 5" class="five-stars">5</a></li>
</ul>
<div id="itemRatingLog16441" class="itemRatingLog" itemprop="reviewCount">(0 votes)</div>
<div class="clr"></div></div><div class="clr"></div></div>