不使用SmsManager Android Studio

Question

每当我点击我的应用中的按钮时，我都会尝试向我的电话号码发送消息。应用说“消息成功发送”，但我没有得到任何短信。我不确定我的电话号码格式或我的smsmanager功能是不正确的。这是我的代码。任何帮助将是欣赏。谢谢。

public void sendSmsByManager() {
    try {
        // Get the default instance of the SmsManager
        SmsManager smsManager = SmsManager.getDefault();
        PendingIntent sentPI;
        String SENT = "SMS_SENT";

        sentPI = PendingIntent.getBroadcast(this, 0,new Intent(SENT), 0);


        //phone number format is Malaysia +60134567891
        smsManager.sendTextMessage(phoneNumber.getText().toString(), 
                null,  
                smsBody.getText().toString(), 
                sentPI,
                null);


        Toast.makeText(getApplicationContext(), "Your sms has successfully sent!",
                Toast.LENGTH_LONG).show();
    } catch (Exception ex) {
        Toast.makeText(getApplicationContext(),"Your sms has failed...",
                Toast.LENGTH_LONG).show();
        ex.printStackTrace();
    }
}