app/src/main/res/menu/top_menu_bar.xml
<?xml version="1.0" encoding="utf-8"?>
<menu
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".MainActivity">
<item
android:id="@+id/action_settings"
android:orderInCategory="300"
android:title="Settings"
android:icon="@drawable/ic_baseline_settings_20px"
app:showAsAction="ifRoom" />
</menu>