GetOrders SP-API Sandbox : Error 400 again ?

[guldil]

Problem description:

It is my first development with SP-API and i can't get a "test connecton" working.
I created a developper account in solutionproviderportal and a SandBox application.
I have client id, client secret and i create a refresh token from solutionproviderportal too.
I'm waiting for access to a true Seller Account from my client.
I'm in France so i test with EU_SANDBOX and A13V1IB3VIYZZH from MarketPlace ID.
I read all the issues about error 400, none of these correspond to my problem

Error:

Get orders Failed.

In RequestException.php line 111:
                                                                                                                                                                                     
  Client error: `GET https://sandbox.sellingpartnerapi-eu.amazon.com/orders/v0/orders?MarketplaceIds=A13V1IB3VIYZZH&CreatedAfter=2025-09-01T00%3A00%3A00Z` resulted in a `400 Bad    
  Request` response:                                                                                                                                                                 
  {                                                                                                                                                                                  
    "errors": [                                                                                                                                                                      
      {                                                                                                                                                                              
        "code": "InvalidInput",                                                                                                                                                      
        "message": "Could not match input arguments",                                                                                                                                
        "details": (truncated...)

Code

<?php

namespace App\Command;

use SellingPartnerApi\SellingPartnerApi;
use SellingPartnerApi\Enums\Endpoint;
use Psr\Http\Message\RequestInterface;
use Saloon\Http\PendingRequest;
use Symfony\Component\Console\Attribute\AsCommand;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Console\Style\SymfonyStyle;

#[AsCommand(
    name: 'amazon:test-connection',
    description: 'Teste la connexion à l\'API Amazon SP-API (Orders)',
)]
class AmazonTestConnectionCommand extends Command
{
    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        //try {
            $connector = SellingPartnerApi::seller(
                clientId: $_ENV['AMAZON_CLIENT_ID'],
                clientSecret: $_ENV['AMAZON_CLIENT_SECRET'],
                refreshToken: $_ENV['AMAZON_REFRESH_TOKEN'],
                endpoint: Endpoint::EU_SANDBOX,  // Or Endpoint::EU, Endpoint::FE, Endpoint::NA_SANDBOX, etc.
            );

            //debug request
            $connector->debugRequest(
                function (PendingRequest $pendingRequest, RequestInterface $psrRequest) {
                    var_dump($pendingRequest->headers()->all(), $psrRequest);
                }
            );

            $ordersApi = $connector->ordersV0();
            $response = $ordersApi->getOrders(
                ['A13V1IB3VIYZZH'],
                '2025-09-01T00:00:00Z'
            );

            $output->writeln('<info>Connexion réussie !</info>');
            $output->writeln(json_encode($response, JSON_PRETTY_PRINT));

            return Command::SUCCESS;
        // } catch (\Throwable $e) {
        //     $output->writeln('<error>Erreur : ' . $e->getMessage() . '</error>');
        //     return Command::FAILURE;
        // }
    }
}

Seller Central SP API config page screenshot

[UtechtDustin]

Works fine for me, as i read in the other issue #592 the sandbox expects static stuff.
Like in you're case you should not pass a date, instead pass the static string TEST_CASE_200.

The Static String is documented e.g. here:
https://github.com/amzn/selling-partner-api-models/blob/f3b0bc6c3949f791589b079e78b341f13f954b41/models/orders-api-model/ordersV0.json#L252

So the solution is to not use

$response = $ordersApi->getOrders(
                ['A13V1IB3VIYZZH'],
                '2025-09-01T00:00:00Z'
            );

Instead us

$response = $ordersApi->getOrders(
                ['A13V1IB3VIYZZH'],
                'TEST_CASE_200'
            );