To allow a student to revise a Quiz or Journal Activity, you must submit that Quiz or Journal Activity to the student for revision. Students cannot revise their submitted work without their teacher returning it to them for revision.
First, click on the student from your Teacher Dashboard, or go to your Data page and select the student.
Locate the quiz or journal activity and click Allow Revision:
This will change the submitted Quiz or Journal Activity to a draft so that the student can edit their work from My Shelf.