build.gradle

implementation 'androidx.coordinatorlayout:coordinatorlayout:1.1.0'

coordinator_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/myCoordinatorLayout"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Here are the existing layout elements, now wrapped in
         a CoordinatorLayout -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <!-- …Toolbar, other layouts, other elements… -->

    </LinearLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

MainActivity.kt

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.view.View
import com.google.android.material.snackbar.Snackbar

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        var snackbar = Snackbar.make(
                findViewById(R.id.myCoordinatorLayout),
                "Name required",
                Snackbar.LENGTH_INDEFINITE
        )

        snackbar.setAction("Go to Error", View.OnClickListener {
            Log.i("RMC", "error")
        })

        snackbar.show()

    }
}