Update, I that I’ve being trying a solution found here - Using Grant Type "Client Credentials" for OAuth2 in HTTP app - #17 by Richard_Johannes
The feedback I’ve had from the system developer is that the parameters look good, but the body of the request is invalid, which is why I’ve been seeing the validation error - the “data” key in your request isn’t valid JSON on my latest attempt. The request content field is correct but is not being passed through as correct JSON. The form is:
But the invalid JSON output is:
{\ngrant_type:"client_credentials",\nclient_id:"XXXXXX",\nclient_secret:"XXXXXX",\nscope:"full_access",\n}
Valid JSON should be:
{“grant_type”:“client_credentials”,“client_id”:“XXXXXX”,“client_secret”:“XXXXXX”,“scope”:“full_access”}
Feels so close to solving this one.