分享视频Facebook没有出现在模态中

Question

我正在尝试通过Facebook FBSDKShareKit共享视频。视频先存储在设备文档的本地，然后再存储在照片库中，然后从那里创建素材资源URL，将其发送到Facebook。

// videoURLString = file:///var/mobile/Containers/Data/Application/5341AB22-ABF3-43BB-8790-A7B5B94FA89F/Documents/video/video.mp4

func copyVideoToAssets(videoURL: URL, completion: @escaping (URL?) -> ()) {
        let photoLibrary = PHPhotoLibrary.shared()
        var videoAssetPlaceholder: PHObjectPlaceholder!
        photoLibrary.performChanges({
            if let request = PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoURL) {
                videoAssetPlaceholder = request.placeholderForCreatedAsset
            }
        }, completionHandler: { success, error in
            if success {
                let options: PHVideoRequestOptions = PHVideoRequestOptions()
                options.version = .current
                options.deliveryMode = .automatic
                options.isNetworkAccessAllowed = true

                let asset = PHAsset.fetchAssets(withLocalIdentifiers: [videoAssetPlaceholder.localIdentifier], options: nil)
                if let phasset = asset.firstObject {

                    PHImageManager.default().requestAVAsset(forVideo: phasset, options: options, resultHandler: {(asset: AVAsset?, audioMix: AVAudioMix?, info: [AnyHashable : Any]?) -> Void in
                        if let urlAsset = asset as? AVURLAsset {
                            let localVideoUrl: URL = urlAsset.url as URL
                            let pathExtension = localVideoUrl.pathExtension
                            let id = phasset.localIdentifier
                            let uuid = id.components(separatedBy: "/")[0]
                            let asseturl = "assets-library://asset/asset.\(pathExtension)?id=\(uuid)&ext=\(pathExtension)"
                            let url = URL(string: asseturl)
                            self.shareVideo(url)
                        } 
                    })
                }
            }
        })
    }

assetURL: assets-library://asset/asset.MP4?id=2777C4AC-1CCC-404C-AFBE-0A0395AF62E0&ext=MP4
func shareVideo(assetURL: URL) {
            let video = FBSDKShareVideo()
            video.videoURL = assetURL
            let content = FBSDKShareVideoContent()
            content.video = video
            self.completion = completion
            self.controller = controller
                FBSDKShareDialog.show(from: controller, with: content, delegate: self)
}

这不起作用，没有视频的共享模式也会出现。