curl --request PUT \
  --url https://api.backside.app/api/v1/events/{id}/attendees/{attendee_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "response_status": "<string>"
}
'

{
  "created_at": "2023-11-07T05:31:56Z",
  "email": "<string>",
  "event_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "metadata": "<unknown>",
  "participant_type": "<string>",
  "response_status": "<string>",
  "role": "<string>",
  "tenant_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "updated_at": "2023-11-07T05:31:56Z",
  "comment": "<string>",
  "contact_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "display_name": "<string>",
  "key_version": 123
}