Get.Key is not working

[selvam920]

return MaterialApp(,
debugShowCheckedModeBanner: false,
navigatorKey: Get.key,
)

error
#0 GetRootState.controller (package:get/get_navigation/src/root/get_root.dart:314:7)
get_root.dart:314
#1 GetNavigationExt.rootController (package:get/get_navigation/src/extension_navigation.dart:1229:51)
extension_navigation.dart:1229
#2 GetNavigationExt.key (package:get/get_navigation/src/extension_navigation.dart:1225:40)

[alok2811]

Change MaterialApp with GetMaterialApp and try