Text editors

i'm doing a course format plugin that has some information that can be set using a text editor.

what does not work yet is uploading pictures - if i click on the "insert picture" icon in the text editor (atto), it will not have a "browse repositories..." button.

if i understand correctly, i have to set the element as trusted and enable pluginfiles? i tried a couple of options, but nothing worked yet

                
$courseformatoptionsedit = array(
                'grading' => array(
                    'label' => get_string('grading', 'format_scfhtw'),
                    'element_type' => 'editor',
                    'options' => array(
                        'noclean' => 1,
                        'trusted' => 1,
                        'trusttext' => 1,
                        'maxfiles' => 5,                        
                    ),

what am i missing?