How can I get JCE Mediabox 2 working in my own component? I can't get it to load images in a popup. It adds the zoom icon, so I guess it's loading, but all images just open in a new window.
I've tried

<a class="jcepopup" data-mediabox="1" href="https://www.joomlacontenteditor.net/<? echo $imgURL; ?>"><img src="https://www.joomlacontenteditor.net/<? echo $imgURL; ?>" alt="Screenshot"/></a>

as well as

<a class="wfpopup wf-zoom-image" href="https://www.joomlacontenteditor.net/<? echo $imgURL; ?>"><img src="https://www.joomlacontenteditor.net/<? echo $imgURL; ?>" alt="Screenshot"/></a>

as well as

$cpex = '<a class="jcepopup" data-mediabox="1" href="https://www.joomlacontenteditor.net/'.$imgURL.'"><img src="https://www.joomlacontenteditor.net/'.$imgURL.'" alt="Screenshot"/></a>';
echo JHtml::_('content.prepare',$cpex);

But neither seem to work. JCE Mediabox is set to load on the component page (and does afaik).
It does work in regular articles.

Here

There's 3 images under the media tab.