curl --request POST \
  --url https://api.everhour.com/projects/{project_id}/fields \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "name": "field name",
  "type": "select",
  "format": {
    "decimals": 2,
    "label": "US$"
  },
  "icon": "<string>",
  "options": [
    {
      "id": 806,
      "name": "option value",
      "color": "#FC5500"
    }
  ]
}
'

{
  "id": 406,
  "name": "field name",
  "type": "date",
  "format": {
    "decimals": 2,
    "label": "US$"
  },
  "options": [
    {
      "id": 806,
      "name": "option value",
      "color": "#FC5500"
    }
  ],
  "position": 1
}