swift can not save .m3u8 file to gallery

Im using this below method to download and save my video to gallery, with .mp4 it's work normally, but when change to .m3u8 it's always fail.

func downloadVideoLinkAndCreateAsset(_ videoLink: String,_ fileName : String) {

        // use guard to make sure you have a valid url
        guard let videoURL = URL(string: videoLink) else { return }

        guard let documentsDirectoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
        let fileNameToSave = "CiviX_HistoryVideo_\(fileName)"
        // check if the file already exist at the destination folder if you don't want to download it twice
        if !FileManager.default.fileExists(atPath: documentsDirectoryURL.appendingPathComponent(fileNameToSave).path) {

            // set up your download task
            URLSession.shared.downloadTask(with: videoURL) { (location, response, error) -> Void in

                // use guard to unwrap your optional url
                guard let location = location else { return }

                // create a deatination url with the server response suggested file name
                let destinationURL = documentsDirectoryURL.appendingPathComponent(fileNameToSave)
                print("destinationURL: \(destinationURL)")
                do {

                    try FileManager.default.moveItem(at: location, to: destinationURL)

                    PHPhotoLibrary.requestAuthorization({ (authorizationStatus: PHAuthorizationStatus) -> Void in

                        // check if user authorized access photos for your app
                        if authorizationStatus == .authorized {
                            PHPhotoLibrary.shared().performChanges({
                                PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: destinationURL)}) { completed, error in
                                    if completed {
                                        print("Video asset created")
                                    } else {
                                        print("Video asset create failed: \(error?.localizedDescription)")
                                    }
                            }
                        }
                    })

                } catch { print("file manager error: \(error.localizedDescription)") }

                }.resume()

        } else {
            print("File already exists at destination url")
        }

    }

then here is method to call

let urlString = response.replacingOccurrences(of: "\"", with: "") -> my m3u8 URL

let videoImageUrl = "https://www.sample-videos.com/video123/mp4/720/big_buck_bunny_720p_1mb.mp4" -> always success

//TEST MP4 file -> ALWAYS SUCCESS
self.downloadVideoLinkAndCreateAsset(videoImageUrl, "big_buck_bunny_720p_1mb.mp4")

//TEST M3U8 FIlE -> FAIL
self.downloadVideoLinkAndCreateAsset(urlString, history.fileName!) -> fileName format is 'abc.mp4'

The log result for MP4

destinationURL: file:///Users/thehe/Library/Developer/CoreSimulator/Devices/05C6DE76-6609-4E4A-B00D-2CE3622D2EF8/data/Containers/Data/Application/90994674-6C07-47F9-A880-D1A80CDA0C27/Documents/CiviX_HistoryVideo_big_buck_bunny_720p_1mb.mp4

-> Video asset created

THe log result for M3U8

self.downloadVideoLinkAndCreateAsset(urlString, history.fileName!)

destinationURL: file:///Users/thehe/Library/Developer/CoreSimulator/Devices/05C6DE76-6609-4E4A-B00D-2CE3622D2EF8/data/Containers/Data/Application/DA6ABC38-4E0A-44C7-9C56-8B65F1DC0D4D/Documents/CiviX_HistoryVideo_20-1-2019_3h18m32s.mp4

-> Video asset create failed: Optional("The operation couldn’t be completed. (Cocoa error -1.)")

I also tried to save with .m3u8 extension but still not working

self.downloadVideoLinkAndCreateAsset(urlString, "TEST_M3U8_FILE.m3u8")

destinationURL: file:///Users/thehe/Library/Developer/CoreSimulator/Devices/05C6DE76-6609-4E4A-B00D-2CE3622D2EF8/data/Containers/Data/Application/9B42A55B-4E3E-4A20-A0DC-6E1ED22471A2/Documents/CiviX_HistoryVideo_TEST_M3U8_FILE.m3u8

-> Video asset create failed: Optional("The operation couldn’t be completed. (Cocoa error -1.)")

M3U8 is an audio playlist file and it cannot be saved to the gallery.