Using php-ews: https://github.com/jamesiarmes/php-ews
I'm able to list events from my own calendar according to this example: https://github.com/jamesiarmes/php-ews/wiki/Calendar:-Get-List-(Retrieving-Id-and-ChangeKey) But after searching for a solution for a few hours I still haven't been able to find a way to access shared calendars.
This question is similar, but has no answer: EWS: Access shared calendars
From looking at that and various other search results (I've googled many variants of "ews shared calendar") I have to find the location of the shared calendar, get the id and then use that. But I haven't been able to do that. Can anyone help?