YEs you are right it should be there and common to have one but we did not needed it for our app so we did not add it to the api hit .
Please add this code in your wplms-customizer.php file in wplms customizer plugin :
add_filter('bp_course_rest_prepare_course',function($response, $data, $request){
if(!empty($data['id'])){
$data['url'] = get_permalink($data['id']);
}
$response = rest_ensure_response( $data );
return $response;
},10,3);