curl --request POST \
  --url https://statsigapi.net/console/v1/holdouts/{id}/overrides \
  --header 'Content-Type: application/json' \
  --header 'STATSIG-API-KEY: <api-key>' \
  --data '
{
  "environmentOverrides": [
    {
      "environment": "staging",
      "unitID": "unit123",
      "passingIDs": [
        "id1",
        "id2"
      ],
      "failingIDs": [
        "id3",
        "id4"
      ]
    }
  ]
}
'

{
  "message": "Holdout Overrides updated successfully.",
  "data": {
    "passingUserIDs": [
      "passing-user"
    ],
    "failingUserIDs": [
      "failing-user"
    ],
    "passingCustomIDs": [
      "passing-custom-id"
    ],
    "failingCustomIDs": [
      "failing-custom-id"
    ]
  }
}