Client portal: Client unable to update a job

Several clients have expressed the which to update the files or add files belonging to a projets. The reasons:

- a file has been forgotten

- a content has been updated

- additional files for the same project and job have arrived.

I do not see any ppossibility to do this.

I see that a discussion was conducted on a similar project 5 years ago: https://xtrf.userecho.com/communities/8/topics/964-can-we-make-it-possible-for-a-client-to-continuously-add-files-to-a-project-through-the-client and that 4 years ago XTRF was supposed to work on features resolving the isse (feature unknown to me).

Who has the same problem and who has found a solution or a workaround?