Uploading Assets to App Store Connect

I want to use Appstore connect's api to upload images using php. But when I finished creating the image and received a response containing the image upload link, I didn't know what to do next. I tried searching but to no avail. Document

Respone url:

"uploadOperations" : [ {
                "method" : "PUT",
                "url" : "https://store-030.blobstore.apple.com/itms6-assets-massilia...",
                "length" : 11097,
                "offset" : 0,
                "requestHeaders" : [ {
                    "name" : "Content-Type",
                    "value" : "image/png"
                } ]
           } ],

I try code: PHP

$url = "https://store-030.blobstore.apple.com/itms6-assets-massilia..."
$imageData = file_get_contents($filePath);
    $responseUpload = $client->put($url,
        [
            'headers' => [
                'Content-Type' => 'image/png',
            ],
            'body' => $imageData
        ]);
echo $responseUpload->getStatusCode() . PHP_EOL;
var_dump($responseUpload->getBody()->getContents());

Response: 200, string(2) "{}". I don't know why it's wrong

Hope everybody help please.