SPI_code Request does not work.

[phploader]

Hello,
I tried to get this project running, however I had difficulties with some related components (probably the current combination is not working anymore) to get it running.

I basically don't need a template but only the function to make this work. I have written the following code for this and having trouble getting the necessary spapi_code at the last step (line 46).

Basically that is where I am trying to use the selling-partner-api, something is not working.

<?php
error_reporting(E_ALL);
ini_set('display_errors',1);
require_once __DIR__ . "/selling-partner-api/vendor/autoload.php";
$SET = [
	'LWA_CLIENT_ID'		=> 'amzn1.application-oa2-client.XXXX', #'lwaClientId',		
	'LWA_CLIENT_SECRET'	=> '7904a8a8XXXXXX', #'lwaClientIdSecret',
	'awsAccessKeyId'	=> 'AKIA4RXXXXX', #'awsAccessKey',
	'awsSecretAccessKey'=> 'sLX3zog3eJRiNaLwXXXXX', #'awsSecretKey'
	'REDIRECT_URL'	=> 'https://XXXX.XX/',
];
use GuzzleHttp\Psr7\Uri;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
$D = $_REQUEST;
if($D['amazon_callback_uri']) { #1. Rückmeldung	
	echo "<a href='{$D['amazon_callback_uri']}?redirect_uri={$SET['REDIRECT_URL']}oauth&amazon_state={$D['amazon_state']}&state=myState&version=beta'>Next 1</a>";
}else if($D['spapi_oauth_code']) { #2. Rückmeldung
	echo "Bitte Sichern:<br>";
	echo "spapi_oauth_code: <input value='{$D['spapi_oauth_code']}'><br>";
	echo "mws_auth_token: <input value='{$D['mws_auth_token']}'><br>";
	echo "selling_partner_id: <input value='{$D['selling_partner_id']}'><br>";
	echo "<br>";
	$_ENV = [
			'LWA_CLIENT_ID'		=> $SET['LWA_CLIENT_ID'], #'lwaClientId',		
			'LWA_CLIENT_SECRET'	=> $SET['LWA_CLIENT_SECRET'], #'lwaClientIdSecret',
			'awsAccessKeyId'	=> $SET['awsAccessKeyId'], #'awsAccessKey',
			'awsSecretAccessKey'=> $SET['awsSecretAccessKey'] #'awsSecretKey'
			];
		 $client = new GuzzleHttp\Client();
		$res = null;
	$res = $client->request("POST","https://api.amazon.com/auth/o2/token", [
		'headers' => [
						'content-type' => 'application/x-www-form-urlencoded;charset=UTF-8',
					],
		'body' => json_encode ( [
								"grant_type" => "authorization_code",
								"code" => $D['spapi_oauth_code'],
								'redirect_uri' => "{$SET['REDIRECT_URL']}oauth",
								"client_id" => $_ENV["LWA_CLIENT_ID"],
								"client_secret" => $_ENV["LWA_CLIENT_SECRET"],
								] )
		]);
        try {
			$res = $client->post("https://api.amazon.com/auth/o2/token", [ 
				GuzzleHttp\RequestOptions::JSON => [
				"grant_type" => "authorization_code",
				"code" => $D['spapi_oauth_code'],
				'redirect_uri' => "{$SET['REDIRECT_URL']}oauth",
				"client_id" => $_ENV["LWA_CLIENT_ID"],
				"client_secret" => $_ENV["LWA_CLIENT_SECRET"],
				]
			]);
			echo "<pre>";
			print_R($res);
			echo "</pre>";
		}
		catch (GuzzleHttp\Exception\ClientException $e) {
			echo "<textarea style='width: 1000px;height:200px;'>";
			#echo $e->getMessage() . "\n";
			#echo $e->getRequest()->getMethod();
			print_R($e->getResponse());
			echo "\nAntwort:-------------------\n";
			$info = json_decode($e->getResponse()->getBody()->getContents(), true);
			if ($info["error"] === "invalid_grant") {
				print_R($info);
			} else {
				throw $e;
			}
			echo "</textarea>";
		}
		echo "<textarea>".print_r($res)."</textarea>";
} else { #Start
	echo "<a href='https://sellercentral.amazon.com/apps/authorize/consent?application_id=amzn1.sp.solution.1bb3d307-6751-444c-9a14-86a48c11a4ac&version=beta'>Amazon Oautch</a>";
	}

I get the following error message at the end when I try to use the spapi_ouatch_code to read out more account credentials.

Fatal error: Uncaught GuzzleHttp\Exception\ClientException: Client error: `POST https://api.amazon.com/auth/o2/token` resulted in a `400 Bad Request` response: {"error_description":"The authorization grant type is not supported by the authorization server","error":"unsupported_gr (truncated...) in /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php:113 Stack trace: #0 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/guzzle/src/Middleware.php(69): GuzzleHttp\Exception\RequestException::create() #1 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(204): GuzzleHttp\Middleware::GuzzleHttp\{closure}() #2 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(153): GuzzleHttp\Promise\Promise::callHandler() #3 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/TaskQueue.php(48): GuzzleHttp\Promise\Promise::GuzzleHttp\Promise\{closure}() #4 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(248): GuzzleHttp\Promise\TaskQueue->run() #5 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(224): GuzzleHttp\Promise\Promise->invokeWaitFn() #6 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(269): GuzzleHttp\Promise\Promise->waitIfPending() #7 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(226): GuzzleHttp\Promise\Promise->invokeWaitList() #8 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/promises/src/Promise.php(62): GuzzleHttp\Promise\Promise->waitIfPending() #9 /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/guzzle/src/Client.php(187): GuzzleHttp\Promise\Promise->wait() #10 /home/xxxx/xxx.xx/oauth.php(42): GuzzleHttp\Client->request() #11 {main} thrown in /home/xxxx/xxx.xx/core/platform/amazonSP/selling-partner-api/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php on line 113

Look at the code. The problem code starts from the following line:

$res = $client->request("POST","https://api.amazon.com/auth/o2/token ....

To note: I have only one Amazon account. So I created the app in the same Amazon account that I am trying to pair my app with. Is this the reason for the problem?