Unable to create project by using Zoho Projects rest api. Error: { "error": {"code": 6831,"message": "Input Parameter Missing" } }

Unable to create project by using Zoho Projects rest api. Error: { "error": {"code": 6831,"message": "Input Parameter Missing" } }

Hi Zoho friends,
I am trying to create a project by using POSTMAN by following the zoho projects rest api documentation.
Headers:  Authorization : Zoho-oauthtoken 1000.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Body :   { "authtoken":"1000.aeec78c22cf0957f69fd9ea6089c447c.8ecbd53da9eb67134f80f8a6f39ffd87","name": "SAP order issue","description": "single_line","strict_project":"1"}

Response Data : 
400 bad request
{
    "error": {
        "code": 6831,
        "message": "Input Parameter Missing"
    }
}

Please help me out. I am of my middle of my projects and it is very urgent for me to deliver.
Thanks
Avijit