What you need to know
Students must upload a file(s) in the "Take-Home Exam" course element and then confirm this upload by clicking on "Final submission".
In the course view of your Take-Home Exam course you can see if there is a "Final submission" in the "Submission date" column of the table in the "Take-Home Exam" course element.
What you have to do
In your Take-Home Exam course, click on the "Take-Home Exam" course element.
In the tab "All participants" you will find all participants who are enrolled in your course.
In the "Submission date" column you can see if files are missing ("Not submitted").
Click on the name of the person whose submission is missing.
Then click on "Collect document(s)".
This enables you to retrieve a file if it has been uploaded, but not confirmed with "Final submission".