I have tried these steps
Use the following steps to generate an access token:
Log in to Admin and click System > Extensions > Integrations to display the Integrations page.
Click Add New Integration to display the New Integration page.
Enter a unique name for the integration in the Name field. Then enter your admin password in the Your Password field. Leave all other fields blank.
Click the API tab. Select the Magento resources the integration can access. You can select all resources, or select a custom list.
Click Save to save your changes and return to the Integrations page.
Click the Activate link in the grid that corresponds to the newly-created integration.
You can store this access token value in the system configuration and fetch it in code.
from another question Is it good to use Access Token in Magento 2 for REST API?
but seems it doesn't work when I try it in Postman. Eve if I give it all access.
"message": "The consumer isn't authorized to access %resources.",
Any idea what am I doing wrong?