One of the items on our 2020 Roadmap is to update to the latest version of Google Play Billing (for in-app purchases and subscriptions). Google will make the use of Billing 3.0 mandatory in August 2021.
The official native extension for In-app purchase, extension-iap, has been updated and a pre-release version is available for you to test. Our preliminary tests show everything to be working well in Android games, but considering how crucial this feature is to Android games we want your help in finding potential problems. If you want to participate in the testing then please go ahead and upgrade your project dependency to:
IMPORTANT: Note the new function iap.acknowledge() which needs to be used on Google Play for non-consumable products and on subscriptions. Purchases which are not acknowledged (via iap.acknowledge) or consumed (via iap.finish) will be refunded by Google.