Install in an existing project

Inside the Project root (The first build.gradle you see), open the build.gradle file:

In that file, find the allprojects block:

/**
 * Top-level build file for ftc_app project.
 *
 * It is extraordinarily rare that you will ever need to edit this file.
 */
buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:4.0.1'
    }
}

// This is now required because aapt2 has to be downloaded from the
// google() repository beginning with version 3.2 of the Android Gradle Plugin
allprojects {
    repositories {
        mavenCentral()
        google()
        jcenter()
    }
}

and modify it to:

allprojects {
    repositories {
        mavenCentral()
        google()
        jcenter()
        maven { url 'https://jitpack.io' }
    }
}

Afterwards, open the build.gradle file inside of TeamCode folder:

and find the lines:

//
// build.gradle in TeamCode
//
// Most of the definitions for building your module reside in a common, shared
// file 'build.common.gradle'. Being factored in this way makes it easier to
// integrate updates to the FTC into your code. If you really need to customize
// the build definitions, you can place those customizations in this file, but
// please think carefully as to whether such customizations are really necessary
// before doing so.


// Custom definitions may go here

// Include common definitions from above.
apply from: '../build.common.gradle'

repositories {
    maven { url = "https://dl.bintray.com/first-tech-challenge/ftcsdk/" }
}

dependencies {
    implementation project(':FtcRobotController')
    annotationProcessor files('lib/OpModeAnnotationProcessor.jar')
}

and update it to:

dependencies {
    implementation project(':FtcRobotController')
    annotationProcessor files('lib/OpModeAnnotationProcessor.jar')

    implementation 'com.github.ftc17191:ftclayer:+'
}

Finally, perform a gradle sync by pressing the elephant icon in the top right of the screen.