close (Client API reference)
Closes the form.
Syntax
formContext.ui.close();
Remarks
The HTML Window.close method is suppressed. To close a form window, you must use this method. If there are any unsaved changes in the form, the user will be prompted whether they want to save their changes before the window closes.
For Microsoft Dynamics 365 for tablets, this method mimics the behavior of the back navigation button.