The Google Play Console currently shows the following warning when using the latest version

We've detected that this app is using an old version of Google Play Billing. By November 1, 2022, all app updates must use Billing Library version 4 or newer. Update to Billing Library 4 before this date.

I believe this is the dependency that needs to be updated? https://github.com/flutter/plugins/blob/a87497f1399cf6b074dc98563168569d8f738348/packages/in_app_purchase/android/build.gradle#L38