curl --request PATCH \
  --url 'https://api.cal.com/v1/attendees/{id}?apiKey=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "email": "[email protected]",
  "name": "<string>",
  "timeZone": "<string>"
}
'

{
  "attendee": {
    "id": 255,
    "bookingId": 313,
    "name": "Justin Doe",
    "email": "[email protected]",
    "timeZone": "Asia/Jerusalem"
  }
}