Add Google Play Services to Processing

I’m trying to add Google Play Services to my project so I can implement Admob and Play Games.
I’ve followed this tutorial and added to my build.gradle file, my top-level build.gradle contains a reference to the google(), and changed AndroidManifest as well, but I get the error “The import cannot be resolved”.
Adding a google play services jar is an old method, so how can I do it?

P.S: If my text is all messed up for you, I apologize. I’m new to the forum.

@Tagedik ===
Are you using AS or Processing?

I’m using Processing

@Tagedik === ok; so how have you changed your gradle build?

Like i said, I added to my build.gradle file and made sure my top-level build.gradle contained a reference to the google().

@Tagedik === yes, you said that; but how have you done? where is your build.gradle?

I am looking for a way to change the build.gradle file, but did not yet found one. Could you please tell me how you changed build.gradle?

@Mesalcode === you cannot find it using P5 before compiling! - That’s why i was asking “how have you done”… You can find it only using AS.