Flutter HTML response instead of json

Question

I am having error, kindly help me with this code, new to Flutter here. When I'm using https://jsonplaceholder.typicode.com/posts it is working fine, but I am receiving error using my company URL, but when I am using postman to POST the company URL it is working fine, kindly refer to my code and the image below.

Code:

   Dio dio = Dio();

  Future postData() async{
    const String pathUrl = 'https://202.57.135.121:8443/icbs/ATMInterfaceListener/mobileAppRegistration';
    //const String pathUrl = 'https://jsonplaceholder.typicode.com/posts';

dynamic data = {
  'email': 'darwikf@gkdkkk.com',
  'password': 'test123456',
  'firstName': 'Darwin',
  'middleName': 'D',
  'lastName': 'L',
  'birthDate': 095545,
  'mobile': 1256789,
  'telephone': 12367891,
  'presentAddress': 'mla',
  'permanentAddress': 'mla',
  'country': 'phl',

  // 'title': 'Darwin',
  // 'body': 'Success',
  // 'userId': '1',
};

try{
  var response = await dio.post(pathUrl, data: data, options: Options(
    followRedirects: false,
    validateStatus: (status) => true,
    headers: {
      'Content-type' : 'application/json; charset=UTF-8',
    }
  ));
  return response.data;
}catch(e){
  print(e);
}

}`

Image Postman

Image Error

Answer 1

This is the exact answer, this works for me.

Dio dio = Dio();
    
Future postData() async{
    const String pathUrl = 'https://202.57.135.121:8443/icbs/ATMInterfaceListener/mobileAppRegistration';
    dynamic data = {
      'email': 'darwikf@gkdkkk.com',
      'password': 'test123456',
      'firstName': 'Darwin',
      'middleName': 'D',
      'lastName': 'L',
      'birthDate': 095545,
      'mobile': 1256789,
      'telephone': 12367891,
      'presentAddress': 'mla',
      'permanentAddress': 'mla',
      'country': 'phl',
    };
    try{
      var response = await dio.post(pathUrl, data: data, options: Options(
          followRedirects: false,
          validateStatus: (status) => true,
          headers: {
            'Content-Type': 'application/x-www-form-urlencoded',
          }
      ));
      return response.data;
    }catch(e){
      print(e);
    }
}