curl --request GET \
  --url https://app.sajn.se/api/v1/custom-fields \
  --header 'authorization: <authorization>'

{
  "customFields": [
    {
      "id": "<string>",
      "name": "<string>",
      "type": "DOCUMENT",
      "inputType": "TEXT",
      "defaultValue": "<string>",
      "required": true,
      "options": "<string>",
      "createdAt": "<any>",
      "updatedAt": "<any>"
    }
  ],
  "totalPages": 123
}