If you ever need to install script on your website that must appear on all pages, you would normally be instructed to add this to either the Header or the Footer of your website.

This because on most websites, no matter what page you're on, there is always a Header or a Footer present.

The best way to install anything to your Header or Footer in EvolutionX is to use the Head or Footer Block.

You can find these in Appearance > Theme Options:

Head:

Footer: