title: Front-end extension on JupyterLab not shown
body: <p>I am trying to figure out why a front-end extension on Jupyterlab is not shown. I am installing a front-end button on JupyterLab as shown below next to the code drop-down:</p>
  <p><a href="https://i.stack.imgur.com/U4bPC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/U4bPC.png" alt="enter image description here" /></a></p>
  <p>But it is shown on jupyterHub properly</p>
  <p><a href="https://i.stack.imgur.com/BgNKK.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BgNKK.jpg" alt="enter image description here" /></a></p>
  <p>I am installing a plugin from here: <a href="https://github.com/ranjiGT/uncodejupyterplugin" rel="nofollow noreferrer">https://github.com/ranjiGT/uncodejupyterplugin</a> Not sure what settings should be enabled to show this.</p>