Google Play Billing Library 3

Hello, i have an app that developed with ionic 3. There is a alert in google play console that my app doesn’t use Google Play Library 3 for in app purchases. If i don’t upgrade 3 from 2 i can not use in app purchases anymore. I searched on internet but i can not find any good solution. How can i upgrade Google Play Library 2 to 3 for my application. Thanks for the help.

what a nice forum. anyone can help about this question for a long time. you think ionic is the best still?