Campaigns Api 1.1

Campaigns Api 1.1

Hi,
we are using zoho Campaigns Api 1.1 but problem is that we are getting following response :
{
    "message": "",
    "version": "1.1",
    "URI": "/api/v1.1/json/listsubscribe",
    "Code": "INVALID_SCOPE",
    "status": "error"
}

I am passing scope = CampaignsAPI
please suggest if i am wrong.