<?php

declare(strict_types=1);

require_once __DIR__.'/out/php/vendor/autoload.php';

use GuzzleHttp\Client;
use OpenAPI\Client\Api\PetApi;
use OpenAPI\Client\Configuration;

$config = Configuration::getDefaultConfiguration()
    ->setApiKey('api_key', 'YOUR_API_KEY');

$api = new PetApi(new Client(), $config);

$pet = $api->getPetById(56);

var_dump($pet);