title: How to set up HTML tracking code in Google tag manager with transaction ID data
body: <p>I have to implement tracking pixel code on my thank you page through google tag manager. There a transaction ID variable in the pixel code to track the transaction. Below is the tracking pixel code.</p>
  
  <pre><code>&lt;iframe src="https://t1.example.com/p.ashx?a=284&amp;e=302&amp;t=TRANSACTION_ID" height="1" width="1" frameborder="0"&gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>How do I set up the tracking tag which can pass the transaction ID from thank you page to the tracking code in GTM?</p>