If you do not have access to the wp-config.php file, you can enable debug messages by adding a debug flag to the Local Storage. This can be done by entering localStorage.setItem('debug', '*') into the console. Now refresh the page and debugging will be on. Console logging can consume browser resources so you'll probably want to turn debugging off once you are finished with it. To turn debugging off, simply enter localStorage.removeItem('debug') into the console and refresh the page.