InControl2 API minimum "role" an "Organisation User" has to have

What is the minimum “role” an “Organisation User” has to have to use the IC2 API call?
I have one set at “Organisation Viewer” as I only want to read data but I keep getting "“Invalid Accessor, Access Denied” when I run my code.
I have the right client id and sec code in the script as it gets to the point of trying to parse the data file when it throws error.
Any help appreciated
thank you.