Cordova navigation bar plugin import = white screen

no matter where i import the plugin (in app components or a page or a service), i get white screen , not just on the device or emulator but also on the web server …

the moment i set it in the constructor

public navi: NavigationBar,

the app whitescreens with error:

ERROR Error: Uncaught (in promise): NullInjectorError: R3InjectorError(HomePageModule)[AppService -> AppService -> NavigationBar -> NavigationBar -> NavigationBar]: 
  NullInjectorError: No provider for NavigationBar!
NullInjectorError: R3InjectorError(HomePageModule)[AppService -> AppService -> NavigationBar -> NavigationBar -> NavigationBar]: 
  NullInjectorError: No provider for NavigationBar!

i followed the instructions in the documentation but it seems broken or im missing something.

please help , thanx