Add Event Description to ICS and Google Calendar Exports

Site URL: https://www.withinpeople.com/events/growing-a-21st-century-business-13may20

Hello all! I was wondering if you knew how to add a calendar description (rather than just event title) to google calendar from event pages? I've already turned on the export tools for google/ICS but it only shows the event TITLE, and no other details. It would be helpful to be able to add a confirmation message and other event details to the squarespace event page so that it automatically carries over to their calendar when they click the export links. Any ideas? Thank you! 

@aniquecoffee1 so far only solution I've found is using a third party like Eventable