Outlook/Teams: Adding a field to 'New Event' form?

Hi All,

I'd like to build in a text/options field to the 'New Event' form that allows colleagues to attach an agenda or other business-relevant information to a meeting request. Ideally, it would be stored in its own field, but if that isn't possible I could push it to the Notes field under a heading that could be picked up in the Graph JSON.

Any thoughts on this?