If you encounter PB-APIM-ERR-1002, Invalid Access Token, try the following solutions:
Check that you used the correct key and secret to generate the OAuth token. Your developer account provides one key and secret for the Sandbox environment and a separate key and secret for the Production environment. To check your keys, log into Developer Hub.
Generate a new OAuth token. Your current token may have expired. An OAuth token is reusable for 10 hours, after which you must generate a new one. See Generate an OAuth Token.
Make sure the quote marks around the OAuth token in the header of your API call are standard ASCII characters and not enhanced double quotes. This can happen, for example, if you stored the token in Microsoft Word. Word replaces the standard quotes with enhanced quotes. See Generate an OAuth Token.