firt init

app/src/main/res/layout/activity_main2.xml

@@ -20,6 +20,7 @@
         android:background="?android:attr/windowBackground"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintLeft_toLeftOf="parent"
+        app:labelVisibilityMode="labeled"
         app:layout_constraintRight_toRightOf="parent"
         app:menu="@menu/bottom_nav_menu" />