Passwordless connection not working for ionic app

I have an Ionic app where i am looking to use passwordless-sms login.
I configured paswordless undet connections and allowed my app. when i am testing from passwrodless Try tab it sends sms to my mobile, but when i am trying to login through app, it does not work, it says something went wrong, please contact technical support.

Do you see any error in the log (Dashboard > Logs)?

CORS issue.
here are the code details:

 let data: {
      "client_id": "myclientid,
      "connection": "sms",
      "phone_number":"phonenumber"
    }
    var url = "https://kimrayokc.auth0.com/passwordless/start";

    var reqHeader = new HttpHeaders({'Access-Control-Allow-Origin':'*' ,
    'Access-Control-Allow-Methods':'GET,PUT,POST,DELETE,OPTIONS', 
   "Accept": "application/json"});

   return  this.http.post(url,data, {headers:reqHeader});

Same thing is working in postman.