How to add ad block inside li tag?

For many years, somehow, I was able to use the HTML selector option to insert an ad inside Li tag, as you see below. It worked great for many years, but after Ad Inserter version 2.7.24, the feature stopped working, meaning that the ad code would be inserted, but ads wouldn’t show.

Searching around the forum, I found that for the HTML selector work, I needed to use the server-side option with the output buffering. I tried this option, but it seems that it’s not working for me since the Ad Insert plugin tries to add more than one block in random places on the page.

So, my question is without using the HTML selector and without enabling output buffering, how can I add an ad block inside the LI tag with the available settings in Ad Inserter?

<ol>
  <li>
   <P>This is the first item in the list.</P>
   <aside>This is Block Ad</aside>
  </li>
  

  <li>
    <P>This is the first item in the list.</P>
 </li>
</ol>