Keystore file does not exist

The debug keystore file isn't in your application's directory, it's in your .android directory. If you're using Windows, it's probably in C:\Users\yourname\.android (where instead of "yourname" use your own User directory).

Once you know where it is, you can run the keytool like this:

    keytool -list -v -keystore "C:\Users\yourname\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

https://chandruscm.wordpress.com/tag/create-android-oauth-client/

https://stackoverflow.com/questions/42663114/keystore-file-does-not-exist