CS-Cart API Add variation group

Question

I am trying to create a variation group via API. I use the exact example from their documentation with no luck...

JSON from the documentation

{
  "product_ids": [
    286,
    287,
    288
  ],
  "code": "MY_GROUP_1",
  "features": [
    {
      "feature_id": 549,
      "purpose": "group_catalog_item"
    }
  ]
}

My JSON with the correct data:

{
    "product_ids": [
        356744,
        356745
    ],
    "code": "2F_7345",
    "features": [
        {
            "feature_id": 200011,
            "purpose": "group_catalog_item"
        }
    ]
}

The response is

{
    "message": "Bad Request: ",
    "messages": {
        "message": ""
    },
    "status": 400
}

If anyone has any ideas I will be very grateful