How could I attach debugger to android app?

Hi! I try to debug android app in a part of push notifications. But I have a trouble to connect a debugger to the app.

Could anyone help me and describe what you do to attach the debugger to the app?

I run yarn android, open Android studio and press ‘attach debugger’ button. Then select the app and press Ok.

But it says ‘cannot find a process’.

Probably, there are other ways to debug android native code?

It says that Reactotron is used.