Event Item

By default, the calendar displays the value of the "text" property in the event boxes.

If you want to display more data, you can customize the event content using onBeforeEventRender event handler:
https://doc.daypilot.org/calendar/event-customization/

Example:

onBeforeEventRender: (args) => {
  args.data.text = `${args.data.text} ${args.data.myField}`; 
}

This assumes the event data item has "myField" property:

const events = [
  {
    start: "2023-05-06T12:00:00",
    end: "2023-05-06T14:00:00",
    id: 1,
    text: "Event 1",
    myField: "my value"
  }
];

You can also use "args.data.html" to set custom raw HTML but don't forget to HTML-encode the user-provided values in this case (you can use DayPilot.Util.escapeHtml(text) to do that).