I unable to authenticate user details of Apigee Sandbox using OAuth2

I am using following proxy API to authenticate my user details from sandboad

curl -i -H ‘Content-Type: application/x-www-form-urlencoded’ -X POST ‘https://beachbody-test.apigee.net/oauthvalidate?grant_type=password’ -d ‘grant_type=password&username=rsekhar&password=xxxxxx’

It gives me following error

{ “fault”: { “faultstring”: “Invalid client identifier {0}”, “detail”: { “errorcode”: “oauth.v2.InvalidClientIdentifier” } } }

If I execute following url from command line http://api.usergrid.com/beachbody/SANDBOX/default

It authenticates my user and return me with valid user details

curl -X POST -H “Content-Type: application/json” -d ‘{“grant_type”:“password”, “username”:“rsekhar”, “password”:“XXXXXX”}’ “http://api.usergrid.com/beachbody/SANDBOX/default

Response:

{ “action” : “post”, “application” : “b9f23e40-3612-11e5-9987-3fe4681a72f2”, “params” : { }, “path” : “/defaults”, “uri” : “https://api.usergrid.com/beachbody/sandbox/defaults”, “entities” : [ { “uuid” : “5373f2ba-7af6-11e6-8d6b-cf2668611110”, “type” : “default”, “created” : 1473910906203, “modified” : 1473910906203, “grant_type” : “password”, “metadata” : { “path” : “/defaults/5373f2ba-7af6-11e6-8d6b-cf2668611110” }, “password” : “XXXXX”, “username” : “rsekhar” } ], “timestamp” : 1473910906183, “duration” : 38, “organization” : “beachbody”, “applicationName” : “sandbox” }

Below you can find my serviceCallout Policy

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> AuthenticateUser false authenticate.response http://api.usergrid.com/beachbody/sandbox/defaults

Kindly advise me on this

Issue was resolved with username and password, we have to use app basic authentication headers then only it will work