Runing on Kirby 3.25 your plugin runs very well. Thanks.
Now I updated to Kirby 3.3.0-rc.4, no content is showing.
It is broken, because you use deprecated code, e.g.:
message: $page->hasVisibleChildren() is deprecated, use $page->hasListedChildren() instead. $page->hasVisibleChildren() will be removed in Kirby 3.5.0.
Removing “'debug' => true,”, then the panel runs…
[Added:]
In the file \site\plugins\kirby-helpsection\includes\api.php there are two changes needed:
$page->hasVisibleChildren() needs to be $pages->hasListedChildren()
and
$pages->visible() needs to be $pages->listed()