Uploading a new version of the attachment through the update form?


I have this approval workflow, where an employee uploads a pdf for approval, if there is comments from his manager he needs to upload a new version, but I dont want him to have access into the sheet, I only want him to use the update form he receive via email, however there is no option to upload a new version of the attachment from

there, Also if i upload with the same file name, it doesnt combine them it will upload it twice

Please let me know if I am missing anything?