Background image on Jasper

Hi there,

I am trying to add a full-bleed background image to my landing page of my website, www.himmelnord.com/main (with the Japer template).

I have the following code in my Advanced option under Design:

body #collection-5bd21543f9619a9338226d1b { background-image: url("https://static1.squarespace.com/static/5b91241031d4df9713d7c234/t/5be7ace50e2e721437a1d8ca/1541909734433/Starry_Spin-up.jpg")}

However, nothing shows up. (I have also experimented with adding the image to other block elements of the page, which gets added successfully.

Any pointers would be much appreciated!

Thank you.

Andreas