HOW TO: Querying an Outlook Calendar using SPFx

I am trying to learn how to query an Outlook calendar (the calendar created when a SharePoint is created) using SPFx.

I previously had a web part badge on our SharePoint that queried a SharePoint calendar (not Outlook calendar) to display which tech was on call for the week.

When they wanted to start adding many other calendar events I recommended that we switch from the SharePoint calendar to the Outlook calendar that was created and linked to our SharePoint when it was created.

I have found documentation on querying the Outlook calendar but all of it is related to looking at MY calendar, not the group calendar. I have found some things in the Power Automate about this but that calls for using a calendar guid but I can't find anything that tells me how to find the guid for the calendar I want.

So, to summarize. I am trying to query an Outlook calendar that is a private group calendar created when our SharePoint was created and I am looking for instructions, a tutorial, something that will allow me to create a badge web part to display the on call technician for the week?

Thank you.