Fixed Backround like on Wix or Wordpress

Site URL: http://www.thejbcave.com

Hey Guys, 

so in the past I had a wordpress and a wix site. Just wanted to see what squarspace hast to offer but couldnt make a fixed backround in my template. I would be very happy now with the result but if I cant get the fixed backround Im out :) Could someone help me please?

On Site URL I give you an example.

 The site link you posted is for a Squarespace site built on a  template in the same discontinured family, Marquee,  as this one: 

https://alex-demo.squarespace.com/

This is its replacement:

https://basil-demo.squarespace.com/