Sr. Developer Advocate
This app uses the fullcalendar.js library in an iframe (not by importing it into the editor). The code uses template literals to merge in your data with a basic HTML doc example for using FullCalendar. I've added click events for clicking an existing event, or an empty space (to add a new event).
Just swap out your event data with the sample data, and connect your queries or functions for editing events in your datasource.