AVAssetExportSession failed to export audio

I am trying to use AVAssetExportSession to export audio form video but every time I try it, it fails and I don't know why ?!

this is the code

import AVFoundation

 protocol AudioExtractionProtocol {
  func extractAudio(from fileUrl: URL, to outputUrl: URL)
}

final class AudioExtraction {
  private var avAsset: AVAsset?
  private var avAssetExportSession: AVAssetExportSession?
  
  init() {}
}

//MARK: - AudioExtraction conforms to AudioExtractionProtocol

extension AudioExtraction: AudioExtractionProtocol {
   func extractAudio(from fileUrl: URL, to outputUrl: URL) {
    createAVAsset(for: fileUrl)
    createAVAssetExportSession(for: outputUrl)
    exportAudio()
  }
}

//MARK: -  Private Methods

extension AudioExtraction {
  private func createAVAsset(for fileUrl: URL) {
    avAsset = AVAsset(url: fileUrl)
  }
  
  private func createAVAssetExportSession(for outputUrl: URL) {
    guard let avAsset else { return }
    avAssetExportSession = AVAssetExportSession(asset: avAsset, presetName: AVAssetExportPresetAppleM4A)
    avAssetExportSession?.outputURL = outputUrl
  }
  
  private func exportAudio() {
    guard let avAssetExportSession else { return }
    print("I am here \n")
    
    avAssetExportSession.exportAsynchronously {
      if avAssetExportSession.status == .failed {
        print("\(avAssetExportSession.status)\n")
      }
    }
  }
}

func test_AudioExtraction_extractAudioAndWriteItToFile() {
  let videoUrl = URL(string: "https://storage.googleapis.com/gtv-videos-bucket/sample/ForBiggerMeltdowns.mp4")!
  let audioExtraction: AudioExtractionProtocol = AudioExtraction()
  
  audioExtraction.extractAudio(from: videoUrl, to: FileMangerTest.audioFile)
  FileMangerTest.tearDown()
}

 class FileMangerTest {
  private static let fileManger = FileManager.default
  
  private static var directoryUrl: URL {
    fileManger.urls(for: .cachesDirectory, in: .userDomainMask).first!
  }
  
  static var audioFile: URL {
    directoryUrl.appendingPathComponent("audio", conformingTo: .mpeg4Audio)
  }
  
  static func tearDown() {
    try? fileManger.removeItem(at: audioFile)
  }
  
  static func contant(at url: URL) -> Data? {
    return fileManger.contents(atPath: url.absoluteString)
  }
}