Set dynamic Spacing in BottomNavigationBarType to "fixed"

lib/app.dart

@@ -139,6 +139,7 @@ class _AppState extends State<App> {
         unselectedItemColor: Colors.grey,
         showUnselectedLabels: true,
         showSelectedLabels: true,
+        type: BottomNavigationBarType.fixed,
 
         currentIndex: currentPage,
         onTap: (item) {