Re-uploaded offer letters not getting stored.

So when we create an offer and download a pre-existing offer letter and after manually making changes in that, re-uploading the offer letter it is not getting uploaded for third party e-signature -Skribble. Third party integration is done in a way that it is working when we simply submit the offer letter but we are not able to fetch the manually added and re-uploaded offer letters. So can I know the table in which they are stored.