Connecting to third party APIs with OAuth

User Not Authenticated. Could not retrieve a new access token with the refresh token. invalid_request, Missing parameters: access_token

Put log statements in postprocessAccessToken

How to add a dynamic variable or system property to a REST header

https://www.servicenow.com/community/developer-forum/how-to-add-system-property-into-rest-message/m-p/2543725 (opens in a new tab)

References