Won't build

I downloaded the MLKit and opened the final project and it won't execute because:

Execution failed for task ':app:processDebugGoogleServices'.
> File google-services.json is missing. The Google Services Plugin cannot function without it.
Searched Location:
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/google-services.json
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/src/nullnull/google-services.json
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/src/debug/google-services.json
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/src/nullnullDebug/google-services.json
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/src/nullnull/debug/google-services.json
/Users/scott/Downloads/mlkit-android-master/custom-model/final/app/src/debug/nullnull/google-services.json

Looks like docs direct me to Firebase on how to get the .json and that was a "fail". I think this is a bad start for a newbie...

Start by opening the final project under custom-model/final and reproduce the ':app:processDebugGoogleServices' failure. Check the documented Firebase setup and the listed app google-services.json locations. Done means the final project builds and executes without the missing-file error, or the setup requirement is clearly documented.

Written by the indexing model from the issue text.