Problemas con Composer y GuzzleHttp

[pateketrueke]

Pues esto me "funciona":

Código PHP:

<?php
 
require_once 'vendor/autoload.php';
$client = new GuzzleHttp\Client();
 
try {
 
  //if using Guzzle 6+ change "body" to "form_params"
  $response = $client->post('https://www.twitchalerts.com/api/v1.0/donations', [
    'form_params' => [
      'access_token'  => 'ACCESS_TOKEN_HERE',
      'name' => 'Thomas',
      'identifier' => '[email protected]',
      'amount' => 50,
      'currency' => 'USD',
      'message' => 'nice!'
    ]
  ]);
 
  $result = $response->json();
 
} catch (Exception $e) {
 
  var_dump($e->getResponse()->getStatusCode());
 
  //failed
  // $result = $e->getResponse()->json();
 
}