curl --request POST \
  --url https://api.dataspike.io/api/v3/sdk/{short_id}/fields \
  --header 'Content-Type: application/json' \
  --header 'ds-api-token: <api-key>' \
  --data '{
  "full_name": "<string>",
  "email": "<string>",
  "phone": "<string>",
  "country": "<string>",
  "dob": "<string>",
  "gender": "M",
  "citizenship": "<string>",
  "address": "<string>",
  "custom_fields": {}
}'

{
  "message": "<string>"
}