无法使用图片库- ionic 3在iOS设备中保存图像

<edit-config file="*-Info.plist" mode="merge" target="NSPhotoLibraryUsageDescription">
    <string>需要访问相册以保存图像</string>
</edit-config>

npm install @ionic-native/photo-library

import { PhotoLibrary } from '@ionic-native/photo-library/ngx';

constructor(private photoLibrary: PhotoLibrary) { }

saveImageToLibrary(imageUrl: string) {
  this.photoLibrary.requestAuthorization().then(() => {
    this.photoLibrary.saveImage(imageUrl, 'MyApp').then(() => {
      console.log('图片保存成功');
    }).catch((error) => {
      console.log('保存图片时出错：', error);
    });
  }).catch((error) => {
    console.log('请求权限时出错：', error);
  });
}