curl --request POST \
  --url https://api.bold-factory.com/v1/production/recipeVersions/{versionReference}/operations/{operationReference}/coProducts \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "skuReference": "<string>",
  "quantity": "<string>",
  "frequency": 123,
  "externalReference": "<string>"
}
'

{
  "id": "<string>",
  "externalReference": "<string>",
  "skuId": "<string>",
  "sku": {
    "id": "<string>",
    "externalReference": "<string>",
    "code": "<string>",
    "name": "<string>",
    "status": "<string>",
    "productId": "<string>",
    "managesLots": true,
    "unit": {
      "id": "<string>",
      "code": "<string>",
      "name": "<string>"
    },
    "displayDecimalPlaces": 123
  },
  "quantity": "<string>",
  "frequency": 123,
  "conditionFormula": "<string>"
}