WPLMS Show Course online/offline status in Course details

functions.php

add_filter('wplms_course_details_array',function($details){
        $details['unit_duration'] = array(
            'label'=>_x('Course Offline/Online Status','label in details array','vibe-customtypes'),
            'callback'=> 'custom_get_course_offline_online_status',
        );
        return $details;
    });

    function custom_get_course_offline_online_status(){
        $offline = get_post_meta(get_the_ID(),'vibe_course_offline',true);

        return '<li>'._x("Type","Course Detail Sidebar Average Rating","vibe-customtypes").'<i class="course_detail_span">'.(($offline === 'S')?'Offline':'Online').'</i></li>';    
    }