curl --request PATCH \
  --url https://api.maildiver.com/v1/audiences/{audienceId}/contacts/{contactId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "email": "suppressionlist+9@simulator.amazonses.com",
  "first_name": "John",
  "last_name": "Doe",
  "is_subscribed": true
}
'

{
  "message": "Contact updated"
}