title: Magento2 get the product URL in invoice mail
body: <p>I want to make the items clickable in the transactional mails. I modified the order mail (items/default.phtml) and added the following code:</p>
  
  <pre><code>&lt;?php $_item = $block-&gt;getItem() ?&gt;
  &lt;a href="&lt;?= $_item-&gt;getProductUrl(); ?&gt;"&gt; &lt;?= $block-&gt;escapeHtml($_item-&gt;getName()) ?&gt;&lt;/a&gt;
  </code></pre>
  
  <p>However when I add the same code to the invoice mail (items/default.phtml) the value of getProductUrl() is empty.</p>
  
  <p>How can I access the product URL in the invoice?</p>
  
  <p>Thanks in advance.</p>