Company file GUID

Hi,

I want to see the API s and use them for some customisation of tools.

To get the Company file GUID , i tried used the URL as mentioned in some of the posts

https://api.myob.com/accountright/

But it returns a error   

{"message":"Unauthorized"}

 why is it showing? do i need to have "Administrator" previledge. How can i sort this out .

Any help is appreciated.

Thank you

Rigi