<?php

use AmazonPHP\SellingPartner\Api\AuthorizationSDK;
use AmazonPHP\SellingPartner\Api\CatalogItemSDK;
use AmazonPHP\SellingPartner\Marketplace;
use AmazonPHP\SellingPartner\Regions;
use Buzz\Client\Curl;
use AmazonPHP\SellingPartner\Exception\ApiException;
use AmazonPHP\SellingPartner\OAuth;
use AmazonPHP\SellingPartner\Configuration;
use AmazonPHP\SellingPartner\HttpFactory;
use Nyholm\Psr7\Factory\Psr17Factory;

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

$factory = new Psr17Factory();
$client = new Curl($factory);

$oauth = new OAuth(
    $client,
    $httpFactory = new HttpFactory($factory, $factory),
    $config = Configuration::forIAMUser(
        'lwaClientID',
        'lwaClientID',
        'awsAccessKey',
        'awsSecretKey'
    )
);

$accessToken = $oauth->exchangeRefreshToken('seller_oauth_refresh_token');

$logger = new Logger('name');
$logger->pushHandler(new StreamHandler(__DIR__ . '/sp-api-php.log', Logger::DEBUG));

$catalog = new CatalogItemSDK($client, $httpFactory, $config, $logger);

try {
    $item = $catalog->getCatalogItem(
        $accessToken,
        Regions::NORTH_AMERICA,
        $marketplaceId = Marketplace::US()->id(),
        $asin = 'B07W13KJZC'
    );
    dump($item);
} catch (ApiException $exception) {
    dump($exception->getMessage());
}

<?php 

$configuration->registerExtension(new class implements \AmazonPHP\SellingPartner\Extension {
    public function preRequest(string $api, string $operation, RequestInterface $request): void
    {
        echo "pre: " . $api . "::" . $operation . " " . $request->getUri() . "\n";
    }

    public function postRequest(string $api, string $operation, RequestInterface $request, ResponseInterface $response): void
    {
        echo "post: " . $api . "::" . $operation . " " . $request->getUri() . " " 
            . $response->getStatusCode() . " rate limit: " . implode(' ', $response->getHeader('x-amzn-RateLimit-Limit')) . "\n";
    }
});