Can I edit an attachment to be ‘Required’ instead of ‘Optional’?

From Main Menu > My School Store > SchoolCash Catalog
1. Select Item
2. Click Manage Attachment
3. Click the attachment

4. Select Edit
4. Select Optional

5. Find the student or if wishing to detach all students who have not paid, select the single arrow or double arrow to move student(s) from the attached to the detached column