have you tried via the workflow Automator? Get web request?
To me, that message is saying it cannot validate it due to the code having an invalid value so the code could be wrong,
I use the workflow Automator for most of my work not using Curl/postman, maybe if you can get is to work from the web request then it will confirm the code you are using needs tweaking. if you cannot get to work with workflow Automator then it indicates that the asset itself needs amending?
I can't use WORKFLOW AUTOMATOR because I have set up an EDI (computer data exchange) between our CRM and Freshservice. Deleting a contact or a company works perfectly