title: Flutter web app in a subfolder just returns to the root page
body: <p>I have a Flutter portfolio app at suragch.dev and then a few other web apps in an <code>apps</code> subfolder. However, when I push the changes and try to visit the new Flutter app in the subfolder</p>
  <pre><code>https://suragch.dev/apps/mongoleditor/
  </code></pre>
  <p>it returns to the root Flutter page. In the past I didn't have this problem. In fact, another flutter app in the apps folder works fine:</p>
  <pre><code>https://suragch.dev/apps/mongolcode/
  </code></pre>
  <p>How do I fix this?</p>
  <p><em>I found the answer and will add it below.</em></p>