I have uploaded app before august using api 28, but this app cannot be downloaded from playstore for below android 9 user

I have uploaded app before august using api 28, but this app cannot be downloaded from playstore for below android 9 user, How do I solve this problem?
How do I configure my app so that Android Version 4.0 Users and higher android version users can download and use the app?
If I monetize my app with admob does I need to share the revenue with thunkable?

A post was merged into an existing topic: Everything you need to know about the API 29 Update