AWS API shown "Access to requested resource is denied."

https://developer-docs.amazon.com/sp-api-blog/docs/troubleshooting-selling-partner-api-authorization-errors

I have already follow the steps in the above link and test in postman, I am success to get a access token, but when I get the order, the response still is error with

"message": "Access to requested resource is denied.",

"code": "Unauthorized",

"details": ""