SuiteCRM API login not returning session token


I am trying to utilise SuiteCRM’s API in order to login. I am using Postman to do this. This is what I have so far.

Method: POST,
URL: http://localhost/suitecrm/service/v4_1/rest.php
“method”: “login”,
“input_type”: “JSON”,
“response_type”: “JSON”,
“rest_data”: [
“user_auth”: [{
“user_name”: “graeme”,
“password”: “xxx”
“application” : “”,
“name_value_list” : [""]
Headers: Temporary Headers

When I make the request I get a 200 success response, but that response just returns the documentation and not a session token If anyone has any ideas as to why this might be your help would be greatly appreciated.