The print() method prints the exported image using the browser print() function. There is no way to control how the printed page will look like using the browser API. It can only be set by the user in the print dialog.
If you need more control over the printed page (orientation, paper size, headers, additional text, etc.) it's necessary to create a PDF file. Please see the following tutorial:
https://code.daypilot.org/32360/javascript-monthly-calendar-pdf-export