curl --request GET \
  --url https://api.staging.kathan.tech/campaign/{campaign_id}/recipients \
  --header 'Authorization: Bearer <token>' \
  --header 'X-User-ID: <api-key>'

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>"
    }
  ]
}