Once done, we have to register the new component within the app.module.shared.ts file, just like we did a hundred times already (new lines are highlighted):
[...]
import { LoginComponent } from './components/login/login.component';
import { LoginFacebookComponent } from './components/login/login.facebook.component';
@NgModule({
declarations: [
[...]
LoginComponent,
LoginFacebookComponent,
[...]