Using Zopo Project Api , Issue With api key and ticket id

Using Zopo Project Api , Issue With api key and ticket id

Hi .
 I am using Zoho for first time and i am stuck with the ticket id and api key. i am accessing the zoho project api from third party tool fiddler and i am not able access them . It gives me error code=6890 , message=Invalid Ticket.

Details :
http Get 
Api name 
GetPortals 
Url :  http://projectsapi.zoho.com/restapi/portals/
Parse details :
User-Agent: Fiddler
Content Type: application/json;charset=utf-8
Host: projectsapi.zoho.com