Load plugins for users with no editing permissions
By default, the package only loads plugins if the user has editing permissions. That works most of the time as plugins are used by users editing the page.
On the other hand, if you want to use them in a form displayed on the front end for users with no editing permissions it's possible.
Edit your file application/config/concrete.php and add this to the return value:
'ckeditor_plugin_installer' => [ 'load_plugins_for_non_editors' => true ],