Login error on take thsi course if not logged in

Please add this code in your wplms-customizer.php file in wplms-customizer plugin  :

add_filter('wplms_course_product_id','error_if_not_loggedin',10,2);
function error_if_not_loggedin($link,$course_id){
    if(!is_user_logged_in()){
        $link='?error=login';
        return $link;
    }else{
        return $link;
    }
}