Crashlytics for older Android project projects projects

I am using Android Studio / IntelliJ 12 and the old Android Gradle framework.

When I try to set up my project using Crashlytics, my import does not work (I connected my project to Crashlytics using the red button).

I think that without Gradle / Maven my project does not know where to look for the package com.crashlytics.android.

In the Gradle settings (of another project), I find a couple of Maven links to the Crashlytics package. But when I try to add them to the library through Project strcture -> libraries -> add -> from Maven, I don’t want the files to not be able to be downloaded

Any ideas what I can do to run my old project?

Thank! Ron