• Once the invoice is generated click the Items button (as seen in the image below)
  
  
• You will then see the items in a dropdown with a checkbox for collected
  
  
• In the example image below the admin user could tick one or both items as collected
  
  
• You can also click the Mark Collected button, found in the Actions column, to mark all items as collected in one go
  
  
• The items are now marked as collected (see the green tick icon below)

 

• If you had only marked one out of the two items in the top example image, the number of items collected is displayed in the Collected column (see image below)