OJS3 does not have an actual “unsubmit” option. However, when a new manuscript is submitted, the editor can request new versions of the submission before sending it to review. There is a discussion tool in OJS3 you can use to communicate with the author and it can be used for sending files as well.
Thanks for this information. It was very useful because i have been looking for a way for unsubmit a submitted manuscript back to the authors for corrections before proceeding to Peer Review stage