In this page you'll learn how to update an existing in-app product. Please note that any change to pricing or hosted content (iOS only) should be done in the developer portal of the platforms like explained in here and here.
From the list of products click in the product you wish to update:
At any time you can change the name of your product:
You can also change the SKU of your product although this must always match the one you've inserted in the platform's developer pages:
You can also change the type of product in the Type selector:
This is also something that needs to match your selection in Apple's and Google's portals. It will also influence the way you handle this product in your app, so you shouldn't change the type in a production app without making changes to the app itself.
Finally you can change the platforms in which this product is available:
When you're done making changes in your product, click in the Create button to save it:
In this page you will also be able to delete a product. To do that expand the Options menu and click in Delete: