Hello,. If those documents are enough to be accepted then you can upload. However if they ask you to upload Provisional admission letter then you need to definitely upload. So kindly write a mail to csab Helpdesk stating the same problem and they might help you as soon as possible. Also, state the same problem with other too who is asking you to upload that particular letter. Mail them saying that you have forgotten to download the letter they might help you out on what to do.