<?php

$api_url = "url";
$username = "name";
$password = "hitler";
$ch = curl_init($api_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

curl_setopt($ch, CURLOPT_HTTPHEADER, [
   'Content-Type: application/json'
]);

curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
  'identification' => $username,
  'password'       => $password
]));

$result = curl_exec($ch);
$session = json_decode($result);
$session->token;
$session->userId;