mutation DeleteItemVariationValue($request: DeleteItemVariationValueCommandRequestInput!) {
  DeleteItemVariationValue(request: $request) {
    variationValueId
  }
}

{
  "request": {
    "itemId": "id",
    "variationValueId": "id"
  }
}

{
  "data": {
    "DeleteItemVariationValue": {
      "variationValueId": "id"
    }
  }
}