Modify Lead "Call" Modal/Popup?

I’d like to add a required field to the Event DocType. I will need to modify the Modal that pops up when you click the “New Event” button from the Lead (and other) fields.

How do you modify that?

hello. that work by making the field you want mandatory

I added the field as mandatory, and it doesn’t appear in the Lead-> Event pop-up, so I cannot add an Event from Leads…