When creating a new item, a POS ID number will automatically be created to identify this item on your POS system.

If an item is not appearing on the invoice, please make sure that the item has a POS ID on the dashboard.

If not, 

1. Select the item, and click on DUPLICATE

2. Open the "duplicated" item and verify if the POS id field is filled. If so, please keep this "new" item and delete the "original" one.