Google Play only allows you to add a 'managed' in app product?

I am trying to add a consumable / unmanaged (can be purchased more than once) In - app product, however Google Play only allows you to add a managed product, which can only be purchased once. How can I do this? I am using Unity's built in In - app purchase

 

Consume the purchase?
Then when the consume is success, add anything you want to add to the in game inventory...