XF 2.0 static background image when scrolling

[combatgamez]

what code to I need to add in to make a static background like this website:

https://www.thedarkblues.co.uk/

Thanks in advance.

 

[artscripts]

body {

    background: url( https://you_url.com/name.jpg ) center center no-repeat fixed;

    background-size: cover;

}