JWT API file upload error

I am implementing a script for loading an image and creating a link to it.
but I get the error.
what am i missing?
do i need to add the service account as a user to the menu:
https://app.box.com/master/users -> Users & Groups -> New User Account Details
with the service account data?

response object(stdClass)#1 (17) {
  ["type"]=>
  string(4) "user"
  ["id"]=>
  string(11) "14463115583"
  ["name"]=>
  string(13) "RyanDynamics3"
  ["login"]=>
  string(51) "AutomationUser_1411644_sKaKcWiknb@boxdevedition.com"
  ["created_at"]=>
  string(25) "2020-11-24T00:56:10-08:00"
  ["modified_at"]=>
  string(25) "2020-11-24T00:56:29-08:00"
  ["language"]=>
  string(2) "en"
  ["timezone"]=>
  string(19) "America/Los_Angeles"
  ["space_amount"]=>
  int(10737418240)
  ["space_used"]=>
  int(0)
  ["max_upload_size"]=>
  int(5368709120)
  ["status"]=>
  string(6) "active"
  ["job_title"]=>
  string(0) ""
  ["phone"]=>
  string(0) ""
  ["address"]=>
  string(0) ""
  ["avatar_url"]=>
  string(48) "https://app.box.com/api/avatar/large/14463115583"
  ["notification_email"]=>
  array(0) {
  }
}

the application code I am attaching:

<?php
require 'vendor/autoload.php';

function vd($arr,$name='debug arr '){
echo '<pre>'.$name.' ';
var_dump($arr);
echo '</pre>';
}

function base64_to_jpeg($base64_string, $output_file) {
// open the output file for writing
$ifp = fopen( $output_file, 'wb' );

// split the string on commas
// $data[ 0 ] == "data:image/png;base64"
// $data[ 1 ] == <actual base64 string>
$data = explode( ',', $base64_string );

// we could add validation here with ensuring count( $data ) > 1
fwrite( $ifp, base64_decode( $data[ 1 ] ) );

// clean up the file resource
fclose( $ifp );

return $output_file;
}

function get_current_file_url($Protocol='http://') {
//return $Protocol.$_SERVER['HTTP_HOST'].str_replace($_SERVER['DOCUMENT_ROOT'], '', realpath(__DIR__));
return $Protocol.$_SERVER['HTTP_HOST'] . substr($_SERVER['REQUEST_URI'], 0, strrpos($_SERVER['REQUEST_URI'], "/"));
}

/* /////////////////////// GET TOKEN PART ///////////////////////*/

$json = file_get_contents('config.json');
$config = json_decode($json);

$private_key = $config->boxAppSettings->appAuth->privateKey;
$passphrase = $config->boxAppSettings->appAuth->passphrase;
$key = openssl_pkey_get_private($private_key, $passphrase);

$authenticationUrl = 'https://api.box.com/oauth2/token';

$claims = [
'iss' => $config->boxAppSettings->clientID,
'sub' => $config->enterpriseID,
'box_sub_type' => 'enterprise',
'aud' => $authenticationUrl,
'jti' => base64_encode(random_bytes(64)),
'exp' => time() + 45,
'kid' => $config->boxAppSettings->appAuth->publicKeyID
];

use \Firebase\JWT\JWT;
$assertion = JWT::encode($claims, $key, 'RS512');

use GuzzleHttp\Client;

$params = [
'grant_type' => 'urn:ietf:params:oauth:grant-type:jwt-bearer',
'assertion' => $assertion,
'client_id' => $config->boxAppSettings->clientID,
'client_secret' => $config->boxAppSettings->clientSecret
];

$client = new Client();
$response = $client->request('POST', $authenticationUrl, [
'form_params' => $params
]);

$data = $response->getBody()->getContents();
$access_token = json_decode($data)->access_token;
//vd($access_token,'access_token');die();
//vd(json_decode($data),'data');die();

/* /////////////////////// GET TOKEN PART ///////////////////////*/

/* /////////////////////// UPLOAD PART ///////////////////////*/
$orderId = $_POST['orderId'];
$image_base64 = $_POST['imageBase64'];

//$image_base64 = use this variable to receive base64
require_once 'image.php';
//$orderId = 'https://voltacann.com/wp-json/wc/v3/orders/2463';
$orderId = '2463';

$image['name'] = rand(0,time()).'_'.time().'.jpg';
$image['url'] = base64_to_jpeg($image_base64,"upload_images/".$image['name']);
$image['type'] = pathinfo($image['url'], PATHINFO_EXTENSION);
//vd($image,'image');
//get real path for cUrl
$image_realpath = realpath("upload_images/".$image['name']);
//vd($image_realpath,'image_realpath');
$url = "https://upload.box.com/api/2.0/files/content";
$json_attributes = json_encode(array(
"name" => $image["name"],
"parent" => array("id" => "126219502011")//id folder in box.com
));
//get real path for cUrl
$image_realpath = realpath("upload_images/".$image['name']);
$fields = array(
'attributes' => $json_attributes,
'file' => @new CurlFile($image_realpath, $image['type'], $image['name']),
);
//vd($fields,'fields');
$upload_response = array();
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL, $url);
$headers = array();
$headers[] = 'Authorization: Bearer '.$access_token;
//$headers[] = 'As-User:'. 14434726963;
$headers[] = 'Content-Type:multipart/form-data';
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
$upload_response = json_decode(curl_exec($ch));
curl_close($ch);
if($upload_response->type != 'error') unlink($image_realpath);
vd($upload_response,'upload_response');
die();
/* /////////////////////// UPLOAD PART ///////////////////////*/

/* /////////////////////// SHARE PART ///////////////////////*/

$fileId = 745158812846;
$fileId = $upload_response->entries[0]->id;

$url = "https://api.box.com/2.0/files/$fileId?fields=shared_link";
$json = json_encode(array(
'shared_link' => array(
'access' => 'open',
"permissions"=>array(
"can_preview"=> true,
"can_download"=> true
)
)
));
$share_response = array();
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://api.box.com/2.0/files/'.$fileId.'?fields=shared_link');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
$headers = array();
$headers[] = 'Authorization: Bearer '.$access_token;
$headers[] = 'Content-Type: application/x-www-form-urlencoded';
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
$share_response = json_decode(curl_exec($ch));
vd($share_response,'share_response');
if (curl_errno($ch)) {
echo json_encode(array(
'error' => curl_error($ch)
));
}
curl_close($ch);

$result = array(
'imageUrl' => $share_response->shared_link->download_url,
'orderId' => orderId
);

echo json_encode($result);