If you have submitted an application and then at a later date realise there's a mistake or there's something you would like to add, don't worry.
Simply find the job advert and reapply for the job.
When the new application is created, your last application submitted application will pre-populate into the matching fields and you can overwrite the incorrect details or add anything you would like.
When you submit your corrected application this will replace your previously submitted version.