Thank you for reaching out to the Zoom Developer Forum. While we don’t have an API just for instant meetings, you can use the List Meetings API and filter based on type.
Thank you for pointing that out, looks like we have some conflicting documentation there. You’re right though, this API doesn’t return instant meetings. That’s my mistake!
With that being said, what is the use case for listing instant meetings? They should be created as needed. Are you using the Create a Meeting API to create the meeting and then are attempting to list it?