rest api response issue "USER_NOT_AUTHORIZED"

[ismailalabou]

api call response:

{
    "errors": [
        {
            "name": "NOT_AUTHORIZED",
            "message": "Not Authorized",
            "debug_id": "3c49c4c0bc4ba",
            "details": [
                {
                    "field": "#/transaction_id",
                    "value": "51M282532U8742612",
                    "location": "body",
                    "issue": "USER_NOT_AUTHORIZED"
                }
            ]
        }
    ]
}

 plus here is my get call:

https://api-m.sandbox.paypal.com/v1/shipping/trackers/51M282532U8742612-XYZ123456

PS: I believe that my partner sandbox account and API credentials are correct.

here is my cURL code:

curl --location --request GET 'https://api-m.sandbox.paypal.com/v1/shipping/trackers/51M282532U8742612-XYZ123456' \
--header 'Content-Type: application/json' \
--header 'Bearer: ...' \
--header 'Authorization: Basic ...'