We made an application and an error pops up in it. (The app crashed again.) How to find the problem?

Question

Android

We created an android application and it periodically turns off with this error. On different versions of android and all at different times. (The app crashed again.) Please tell me how to find the problem?

Answer 1

https://play.google.com/apps/publish
Select
Android Vitals App
ANR Errors and Crashes
Next, you're looking at clusters of errors.

Answer 2

"I hear some kind of underground knocking. Could you tell me where it comes from?".
Do you know how to use a debugger?
Is there an application code?