To access in-app purchasing features, the basic usage is as follows:
On start of layout, use the Add product ID action to add the product IDs you will be using, e.g. "product1,product2,product3".
After that (still in the 'Start of layout' event), use the Request store listing action. This starts downloading the names and prices of the given products. Some platforms require this information to be available for the IAP features to work.
When On store listing success triggers, the product names and prices are available, and purchases can start being made or checked with the Has product condition.
Can you easily describe how to add in-app purchasing features? I can't find "Add product ID action", where is it? How do I do this?