How to use the @nebular/auth.NbOAuth2ResponseType.TOKEN function in @nebular/auth

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    HttpClientModule,

    NbAuthModule.forRoot({
      strategies: [
        NbOAuth2AuthStrategy.setup({
          name: 'google',
          clientId: '806751403568-03376bvlin9n3rhid0cahus6ei3lc69q.apps.googleusercontent.com',
          clientSecret: '',
          authorize: {
            endpoint: 'https://accounts.google.com/o/oauth2/v2/auth',
            responseType: NbOAuth2ResponseType.TOKEN,
            scope: 'https://www.googleapis.com/auth/userinfo.profile',
            redirectUri: 'https://akveo.github.io/nebular/example/oauth2/callback',
          },

          redirect: {
            success: '/example/oauth2',
          },
        }),
      ],
    }),

    NbCardModule,
    NbLayoutModule,
    Oauth2RoutingModule,
  ],
  declarations: [