habitica-android/Habitica/res/menu/menu_full_profile.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=".ui.activities.TaskFormActivity">
    <item android:id="@+id/private_message"
        android:title="PM"
        android:icon="@drawable/ic_action_chat"
        android:orderInCategory="100"
        app:showAsAction="always"
       />
</menu>