The COD charge is created as a "postage item". As soon as you insert two postage items in the order, the traffic light switches. So you have to insert the normal shipping item, e.g. "shipping fee", and a COD item, e.g. "COD fee". In addition, you must mark both items in the article as "Postage item".
If you don't need the postage check or the cash on delivery check, you can also deactivate it for a project. The traffic light will then remain permanently green, even if you have not inserted a postage item.
You can find more information in our manual: