curl --request POST \
  --url https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start \
  --header 'Content-Type: application/json' \
  --cookie JSESSIONID= \
  --data '
{
  "authnIdentifier": "john@example.com",
  "credential": "changeme",
  "guid": "<string>",
  "captchaResponse": "03AOLTBLSSzhhrLdqCb"
}
'

import requests

url = "https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start"

payload = {
    "authnIdentifier": "john@example.com",
    "credential": "changeme",
    "guid": "<string>",
    "captchaResponse": "03AOLTBLSSzhhrLdqCb"
}
headers = {
    "cookie": "JSESSIONID=",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {cookie: 'JSESSIONID=', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    authnIdentifier: 'john@example.com',
    credential: 'changeme',
    guid: '<string>',
    captchaResponse: '03AOLTBLSSzhhrLdqCb'
  })
};

fetch('https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'authnIdentifier' => 'john@example.com',
    'credential' => 'changeme',
    'guid' => '<string>',
    'captchaResponse' => '03AOLTBLSSzhhrLdqCb'
  ]),
  CURLOPT_COOKIE => "JSESSIONID=",
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start"

	payload := strings.NewReader("{\n  \"authnIdentifier\": \"john@example.com\",\n  \"credential\": \"changeme\",\n  \"guid\": \"<string>\",\n  \"captchaResponse\": \"03AOLTBLSSzhhrLdqCb\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("cookie", "JSESSIONID=")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start")
  .header("cookie", "JSESSIONID=")
  .header("Content-Type", "application/json")
  .body("{\n  \"authnIdentifier\": \"john@example.com\",\n  \"credential\": \"changeme\",\n  \"guid\": \"<string>\",\n  \"captchaResponse\": \"03AOLTBLSSzhhrLdqCb\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://nxt-ulm-pdt.m1amdocs.io/platform/rest/v85/session/start")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["cookie"] = 'JSESSIONID='
request["Content-Type"] = 'application/json'
request.body = "{\n  \"authnIdentifier\": \"john@example.com\",\n  \"credential\": \"changeme\",\n  \"guid\": \"<string>\",\n  \"captchaResponse\": \"03AOLTBLSSzhhrLdqCb\"\n}"

response = http.request(request)
puts response.read_body

{
  "displayMessage": "Enter User Inputs",
  "parameters": {},
  "processId": "640b4b3a-dbaf-4b73-abfb-979475aee0bb",
  "processName": "socialFederation.associateSocialMedia_v1.0",
  "stepName": "PasswordPrompt",
  "lastStep": true,
  "output": {},
  "runtimeId": 1,
  "userId": 1,
  "userAuthenticated": true
}

{
  "operationErrors": [
    {
      "code": "authentication-required",
      "message": "Bad Credentials"
    }
  ]
}