Agora-VoiceFX-Extension+ContentView-initial.swift

struct ContentView: View {
  @State var joinedChannel: Bool = false
  static var agview: AgoraViewer = {
    AgoraViewer(
      connectionData: AgoraConnectionData(
        appId: AppKeys.agoraAppId
      ),
      style: .floating
    )
  }()

  var body: some View {
    ZStack {
      VideoCallView(joinedChannel: $joinedChannel)
      if !joinedChannel {
        Button("Join Channel") {
          self.joinChannel()
        }
      }
    }
  }

  func joinChannel() {
    self.joinedChannel = true
    ContentView.agview.join(
      channel: "test", with: AppKeys.agoraToken,
      as: .broadcaster
    )
  }
}

Agora-VoiceFX-Extension-GetVoiceFilter.swift

enum VoiceEffect {
  case echo(EchoVoiceEffectConfiguration)
  case reverb(ReverbVoiceEffectConfiguration)
  case flanger(FlangerVoiceEffectConfiguration)
  case pitch(PitchShiftVoiceEffectConfiguration)
}

func getVoiceFilter(from name: String) -> VoiceEffect? {
  if name == "echo" {
    return .echo(EchoVoiceEffectConfiguration(mix: 1.0))
  } else if name == "reverb" {
    return .reverb(ReverbVoiceEffectConfiguration(
      dry: 0.9, wet: 0.3, mix: 0.6, width: 1.0,
      damp: 1.0, roomSize: 1.0, preDelay: 300.0, lowCut: 5.0
    ))
  } else if name == "flanger" {
    return .flanger(FlangerVoiceEffectConfiguration(
      wet: 1.0, depth: 1.0, lfoBeats: 30.0, bpm: 100.0, stereo: true
    ))
  } else if name == "pitch shift" {
    return .pitch(PitchShiftVoiceEffectConfiguration(shift: 500))
  }
  return nil
}

Agora-VoiceFX-Extension-menu.swift

VStack {
  HStack {
    Spacer()
    Menu {
      ForEach(values: names) { name in
        Button {
          selection = name
        } label: {
          Text(name)
        }
      }
      if selection != nil {
        Button {
          selection = nil
        } label: {
          Text("Clear")
          Spacer()
          Image(systemName: "clear")
        }
      }
    } label: {
      Image(systemName: "speaker.wave.3")
      Text(selection ?? "Select a Voice Effect")
    }.padding(3).background(Color.black)
    	.cornerRadius(3.0)
    	.onChange(of: selection, perform: { value in
        // update value for voice FX
        self.setVoiceFxParam(to: selection ?? "null")
    })
    Spacer()
    if selection != nil {
      Button {
        selection = nil
      } label: {
        Image(systemName: "xmark.circle")
      }.padding(.trailing, 10)
    }
  }
  Spacer()
}

Agora-VoiceFX-Extension-RegisterVoice.swift

struct VideoCallView: View {

  // other content...

  @State var voiceFxRegistered = false

  func setVoiceFxParam(to voiceName: String) {
    if !self.voiceFxRegistered {
      self.registerVoiceFX()
    }

    // Apply Voice Effects...
  }

  func registerVoiceFX() {
    // Set API Credentials
    ContentView.agview.viewer.setExtensionProperty(
      VoiceFiltersAgoraExtensionVendor, extension: VoiceFiltersAgoraExtensionName,
      key: VoiceFiltersAgoraExtensionApiKey, value: AppKeys.voiceFxApiKey
    )
    ContentView.agview.viewer.setExtensionProperty(
      VoiceFiltersAgoraExtensionVendor, extension: VoiceFiltersAgoraExtensionName,
      key: VoiceFiltersAgoraExtensionApiSecret, value: AppKeys.voiceFxApiSecret
    )

    ContentView.agview.viewer.enableExtension(
      withVendor: VoiceFiltersAgoraExtensionVendor,
      extension: VoiceFiltersAgoraExtensionName, enabled: true
    )
    self.voiceFxRegistered = true
  }
}

Agora-VoiceFX-Extension-SetVoice.swift

struct VideoCallView: View {

  // other content...

  static let voiceFilter: SynervozVoiceFilter = SynervozVoiceFilter()

  func setVoiceFxParam(to voiceName: String) {
    if !self.voiceFxRegistered {
      self.registerVoiceFX()
    }

    let newVoice = self.getVoiceFilter(from: voiceName)
    let agoraEngine = ContentView.agview.viewer.agkit
    switch newVoice {
      case .echo(let echoConfig):
      VideoCallView.voiceFilter.setEcho(echoConfig, inEngine: agoraEngine)
      case .reverb(let reverbConfig):
      VideoCallView.voiceFilter.setReverbConfiguration(reverbConfig, inEngine: agoraEngine)
      case .flanger(let flangerConfig):
      VideoCallView.voiceFilter.setFlangerConfiguration(flangerConfig, inEngine: agoraEngine)
      case .pitch(let pitchShiftConfig):
      VideoCallView.voiceFilter.setPitchShiftConfiguration(pitchShiftConfig, inEngine: agoraEngine)
      case .none: break
    }
    VideoCallView.voiceFilter.enableEcho("echo" == voiceName, inEngine: agoraEngine)
    VideoCallView.voiceFilter.enableReverb("reverb" == voiceName, inEngine: agoraEngine)
    VideoCallView.voiceFilter.enableFlanger("flanger" == voiceName, inEngine: agoraEngine)
    VideoCallView.voiceFilter.enablePitchShift("pitch shift" == voiceName, inEngine: agoraEngine)
  }
}