Problem in Adding Trait

[Rishabh Bhardwaj]

Hi,

I am working on adding Trait to an entity,
I am making the following API call and getting 404,

http://localhost:21000/api/atlas/entity/340eb4bf-776c-4474-b15f-4c8bae1b5bb8/traits

Post Body:
{

"jsonClass":"org.apache.atlas.typesystem.json.InstanceSerialization$_Struct",
  "typeName":"FirstTrait",
  "values":{

  }
}

The trait `FirstTrait` is already created.
Kindly Help.

Thanks,
Rishabh.