import { NgbModule } from '@ng-bootstrap/ng-bootstrap'
import { NgbModalModule } from '@ng-bootstrap/ng-bootstrap'

imports: [
    CalendarModule.forRoot({
      provide: DateAdapter,
      useFactory: adapterFactory
    }),
    NgbModule,
    NgbModalModule,
    FlatpickrModule.forRoot(),
    CalendarModule.forRoot({
      provide: DateAdapter,
      useFactory: adapterFactory
    }),

Uncaught TypeError: Object(...) is not a function
    at ng-bootstrap.js:146
    at Module../node_modules/@ng-bootstrap/ng-bootstrap/fesm5/ng-bootstrap.js (ng-bootstrap.js:148)
    at __webpack_require__ (bootstrap:78)
    at Module../src/app/app.module.ts (app.component.ts:17)
    at __webpack_require__ (bootstrap:78)
    at Module../src/main.ts (main.ts:1)
    at __webpack_require__ (bootstrap:78)
    at Object.0 (main.ts:12)
    at __webpack_require__ (bootstrap:78)
    at checkDeferredModules (bootstrap:45)