M365: How to access the Outlook calendars of everyone in the company

Hello Makers,

I am creating a workflow to access all Outlook calendars within the company and save their contents as a CSV file. I have created a proof of concept using only my own account and calendar. This works fine — I can retrieve all events and save them in one CSV file.

I have authorised the connection through the Microsoft 365 Calendar – Search Events module via ClientID/ClientSecret/TenantID (access set to calendar read+write). However, in the module settings, I can still only see my calendar through Calendar Groups and under my Calendar ID. The same applies to the M365 Calendar – List Calendars module: all I can see is my own calendar. How can I access all calendars under the same M365 account? Can I do that through these modules? Do I need any specific admin access?

Thanks!
Tadeas