Hey @joseph.pradeep, thanks for posting and using Zoom!
The issue is some of the uuids have / in them which messes up the path in the request.
Can you try double url encoding the uuids when calling:
https://api.zoom.us/v2/metrics/webinars/{doubleUrlEncodedUUID}/participants?type=past
https://marketplace.zoom.us/docs/api-reference/zoom-api/dashboards/dashboardwebinarparticipants
More details here:
Let me know if this helps! 
Thanks,
Tommy