Hi @harishknaik93, welcome to the Zoom Community
Are you using the following API Endpoint?
GET /past_meetings/{meetingUUID}/participants
If so, then unfortunately this API is only available for paid accounts (Pro or higher).
https://marketplace.zoom.us/docs/api-reference/zoom-api/meetings/pastmeetingparticipants
Additional information regarding the API rate limits for each account type is available here:
https://marketplace.zoom.us/docs/api-reference/rate-limits
Let me know if this answers your question? If so, don’t forget to mark the reply as an accepted solution!