1. In Configuration, click Attributes.
  2. Highlight the attribute type on the left
  3. Mark (to make it required) or unmark (to make it not required) the Required checkbox next to the attribute.
  4. Click File, Exit and Sign out.
  5. Log back in and your changes will have taken effect.

Note: This change is not retroactive. It only affects transactions or records added after the checkbox is marked or unmarked.