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