How add background picture

In the customize section there was no option to add a background photo.
So I added CSS (successfully tested on W3schools.com) but the background remains white.

Below is the CSS code I used

body {
 background-image: url(“https://realfamilytv.club/OrangeFilmStripBkgd.jpg”);
 background-color: #cccccc;
}

The page I need help with: [log in to see the link]