curl --request POST \
  --url https://api.quo.com/tasks/{taskId}/users \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --header 'Quo-Api-Version: <quo-api-version>' \
  --data '
{
  "userId": "US123abc"
}
'

{
  "data": {
    "taskId": "TK123",
    "revision": 2
  }
}

{
  "message": "The input was invalid",
  "docs": "https://quo.com/docs",
  "title": "Bad Request",
  "trace": "6897907457496870895"
}

{
  "message": "User is unauthorized to perform this action",
  "docs": "https://quo.com/docs",
  "title": "Unauthorized",
  "trace": "6897907457496870895"
}

{
  "message": "User is forbidden to perform this action",
  "docs": "https://quo.com/docs",
  "title": "Forbidden",
  "trace": "6897907457496870895"
}

{
  "message": "The contact was not found",
  "docs": "https://quo.com/docs",
  "title": "Not Found",
  "trace": "6897907457496870895"
}

{
  "message": "An unknown error has occurred",
  "docs": "https://quo.com/docs",
  "title": "Unknown Error",
  "trace": "6897907457496870895"
}