curl --request POST \
  --url https://api.staging.kathan.tech/campaign/{campaign_id}/recipients \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-User-ID: <api-key>' \
  --data '
{
  "recipients": [
    {
      "phone_number": "<string>",
      "metadata": {},
      "assistant_overrides": {}
    }
  ]
}
'

{}