Uncaught TypeError: Object (...) не является функцией в приложении ioni c

Question

Я хочу использовать «Камера» в моем приложении ioni c. Скомпилировано успешно, но произошла ошибка. Uncaught TypeError: Object (...) не является функцией. Я не знаю, что это значит .. Пожалуйста, помогите мне ... board.page. html -> btnTakePicture () -> board.page.ts -> btnTakePiture () -> cameraService-> takePircture ()

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { RouteReuseStrategy } from '@angular/router';

import { IonicModule, IonicRouteStrategy } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';

import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';

import {Camera} from '@ionic-native/camera';

@NgModule({
  declarations: [AppComponent],
  entryComponents: [],
  imports: [BrowserModule, IonicModule.forRoot(), AppRoutingModule],
  providers: [
    StatusBar,
    SplashScreen,
    { provide: RouteReuseStrategy, useClass: IonicRouteStrategy },
      Camera
  ],
  bootstrap: [AppComponent]
})
export class AppModule {}

board.page. html

<ion-header>
  <ion-toolbar>
    <ion-title>board</ion-title>
  </ion-toolbar>
</ion-header>

<ion-content>
  <div>
    <div>
      <ul>
        <li (click)="btnTakePicture()"><a class="button button-icon icon ion-camera"></a></li>
      </ul>
    </div>
  </div>
</ion-content>

board.page.ts

import { Component, OnInit } from '@angular/core';
import {CameraService} from '../services/camera.service';

@Component({
  selector: 'app-board',
  templateUrl: './board.page.html',
  styleUrls: ['./board.page.scss'],
})
export class BoardPage implements OnInit {

  constructor(private cameraService: CameraService) { }

  ngOnInit() {
  }

  btnTakePicture() {
    this.cameraService.takePicture();
  }

}

camera.service .ts

import { Injectable } from '@angular/core';
import {Camera, CameraOptions} from '@ionic-native/camera';

@Injectable({
  providedIn: 'root'
})
export class CameraService {
  public photos: any;
  private base64Prefix = 'data:image/jpeg;base64,';

  constructor(private camera: Camera) {
    this.photos = [];
  }

  takePicture() {
    const options: CameraOptions = {
      quality: 100,
      destinationType: this.camera.DestinationType.DATA_URL,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE
    };

    this.camera.getPicture(options).then((imageData) => {
      const safeUrl: any = this.base64Prefix + imageData;
      this.photos.push(safeUrl);
      this.photos.reverse();
    }, (err) => {
      console.log('Camera issue: ' + err);
    });
  }
}