unsupported version of Play billing 4

Questions & Answers
1

a few days ago I updated the game application and got this notification on my google play console account, and I can’t update my game.
is there any solution for this…?

We’ve detected this app uses an unsupported version of Play billing. Please upgrade to Billing Library version 4 or newer to publish this app.

2

Solution:
https://forum.unity.com/threads/unity-iap-package-4-4-1-is-now-available-and-deprecated-asset-store-v2-3-0.415517/page-2#post-8386932

3

Problem fixed here : We've detected this app uses unsupported version of Play billing. Please upgrade to Billing Library - YouTube

4

Here’s a simple 1min fix for play billing library 4: