Swift TextToSpeech sample

TextToSpeech.swift

import UIKit
import AVFoundation

class ViewController: UIViewController {
  
    @IBOutlet weak var txtFieldText: UITextField!
    @IBOutlet weak var labelMessage: UILabel!
    let synth = AVSpeechSynthesizer()
    var myUtterance = AVSpeechUtterance(string: "")
 
    @IBAction func textToSpeechButton(_ sender: UIButton) {

        myUtterance = AVSpeechUtterance(string: txtFieldText.text!)
        myUtterance.rate = 0.4
        myUtterance.pitchMultiplier = 1.2
        myUtterance.postUtteranceDelay = 0.1
        myUtterance.volume = 1
        myUtterance.voice = AVSpeechSynthesisVoice(language: "zh-TW")
        synth.speak(myUtterance)
        
    }
    
    override func viewDidLoad() {

        super.viewDidLoad()
                
        //TTS is working for physical device after adding below code
        do{
            try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)         
            do{
                try AVAudioSession.sharedInstance().setActive(true)
            }catch{
                
            }
        }catch{
            
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }


}

I am converting text to speech and playing it on the Car's bluetooth speaker. But when it plays on the car's bluetooth , the car's bluetooth screen show that it initiated the call on the self number. If the iPhone do not contains the SIM card it starts showing the timer. iPhone has no sign of calling being initiated.

I am using following code to play the text in car's bluetooth :

let audioSession = AVAudioSession.sharedInstance()
try? audioSession.setCategory(AVAudioSession.Category.playAndRecord, mode: AVAudioSession.Mode.default, options: [.defaultToSpeaker, .allowBluetooth,.allowBluetoothA2DP])
do {
try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
} catch {
print("Error in the session")
}

let utterance = AVSpeechUtterance(string: text)
utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
synth.speak(utterance)
synth.continueSpeaking()

I tried using only . allowBluetoothA2DP but audio cannot be heard in Bluetooth speaker when I am doing this