The useIframe property (boolean) specifies whether an iframe is used to display modal dialog content shown using DayPilot.Modal.showHtml().
DayPilot.Modal.useIframetrueThis property applies only to DayPilot.Modal.showHtml(). When you display a separate page using DayPilot.Modal.showUrl(), an iframe is always used.
const modal = new DayPilot.Modal();
modal.useIframe = false;
modal.showHtml("<div>Hello, world!</div>");