Plug-in code into php

Hi all.
This is my site.
In a few words. I want to use this plug-in to set up a slider on my home page background. The code i need to add is :
<?php wd_slider(1); ?>
The problem is that the slider can be seen only when i add it into footer.php or header.php. Based on the line and file i put it in, the slider moves a little bit, but it always moves the navigation menu. I want the background to be behind the menu. According to the plug-in developer i need to add this code into home.php but that doesn’t work.
My php understanding is less than basic. Can someone please help me figure out where should I add the code?
Thank you very much in advance.
Best regards, Vlad!