Add Tracking API in Paypal - Authorization failed - authentication

Question

I am trying to add tracking number and order status in my sandbox account through tracking API but getting "Authorization failed due to insufficient permissions" error. Anyone have any idea why this error happens? Below are my codes and response from paypal -
API request
$clientId = 'my client id';
$secretKey = 'my secret key';
$token = $this->getAccessToken($clientId, $secretKey);
$transaction = $this->_objectManager->create('\Magento\Sales\Api\Data\TransactionSearchResultInterfaceFactory')->create()->addOrderIdFilter($currentOrder->getId())->getFirstItem();
$transactionId = $transaction->getData('txn_id');
$postfields = [
'trackers' =>
[
0 =>
[
'transaction_id' => $transactionId,
'tracking_number' => $currentOrderTrackingNumber,
'status' => 'SHIPPED',
'carrier' => 'OTHER',
'carrier_name_other' => 'SCS Logistics'
]
]
];
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => "https://api-m.sandbox.paypal.com/v1/shipping/trackers-batch",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode($postfields),
CURLOPT_HTTPHEADER => array(
"Content-Type: application/json",
"Authorization: Bearer " . $token
),
));
$response = curl_exec($curl);
curl_close($curl);
$response = json_decode($response, true);
Response from paypal
Array
(
[tracker_identifiers] => Array
(
)
[errors] => Array
(
[0] => Array
(
[name] => NOT_AUTHORIZED
[message] => Authorization failed due to insufficient permissions
[details] => Array
(
[0] => Array
(
[field] => /trackers/1/transaction_id
[value] => 42L93730906985049
[location] => body
[issue] => USER_NOT_AUTHORIZED
[description] => You are not authorized to add or modify tracking number for this transaction
)
)
[links] => Array
(
)
)
)
[links] => Array
(
[0] => Array
(
[href] => https://api-m.sandbox.paypal.com/v1/shipping/trackers-batch
[rel] => self
[method] => POST
[encType] => application/json
)
)
)
I already contacted support and they added required permission but it's not working. Please if anyone have any idea about it help me. Thanks in advance.