I tried to retrieve my eventbrite events using an API private token and my organization ID found in :
https://www.eventbrite.fr/organizations/info/profile/456xxxxxxx so I took this organisation ID and I plugged it in :
$eventbrite->get('organizations/'.$id_organisation.'/events/', ['status' => 'live']); .
This didn't yield any result.
Finally, I managed to retrieve the list of my eventbrite events using the same private token but with an organisation ID that I got from the URL https://www.eventbrite.fr/u/123xxxxxxx/favorites/events. What makes me wonder is that why did the API call manage to get me the events using an ID that is not id of the organization ? It is some sort of user id no ?
This might answer your question. From Eventbrite docs:
If you don't belong to any Organizations, your user_id is your default Organization ID.