Using older version of Google Play Developer API

When I updated an app in Google Play Store with SAB 5.6, I got the below warning message.

We’ve detected that your app is using an old version of the Google Play Developer API. From December 1 2019, versions 1 and 2 of this API will no longer be available. Update to version 3 before this date. Learn more

I am pretty sure @richard and @ChrisHubbard are aware of this.