Since Friday, it has become easier for developers to “dump” in-game currency to testers and journalists. Apple has introduced the ability to make promo codes for in-app purchases.
Earlier, the platform’s toolkit supported only promo codes for paid applications — no more than 100 codes for each version of the application for each type of device (iPhone/iPad/tvOS).
Since yesterday, the developer can already generate more than 100 promo codes for each position in the app store itself. The total limit is no more than 1000 promo codes.
In the event that the application is not installed and is distributed for free, it starts downloading automatically as soon as the user has activated the code. The promo code remains active for 28 days from the date of the request. The codes are linked to a specific version of the application.
Sources: appleinsider.com, developer.apple.com