Calendar Reporting

Hi Nextcloud team , how can I generate report of my calendar. Eg ( task completed, task pending)

Thank in advance

You should create a feature request in https://github.com/nextcloud/tasks/issues

But Iโ€™m not sure if thatโ€™s something @raimund-schluessler wants the be part of the tasks app.
Nonetheless, Nextcloud is using the standardized CalDAV protocol and you can just use any CalDav tool, that can generate these kinds of reports.