You may find an assignment called "Completed Unit Notifications" in your course.
These are used to sign off the overall Competency of a Unit. This task will only become available once ALL the tasks for the unit have been completed and graded and are Satisfactory and the automatic unit checklist signifies that these are complete.
Keep an eye on your grading sheet, and complete this anytime after you notice that all the tasks show as Satisfactory on your grading sheet.
If you have missed this, there is no need to worry, this can also be completed by the assessor.
Just continue to work through the next tasks in the next units while your submitted work is waiting to be graded.
If you don't see this in your course, it does not apply to you.