HTML Embed Code Edit

Hello Community,
I cloned this site. I am trying to edit HTML Embed with Wave on site. I want to replace the background: url(…) and put my own wave that I uploaded to Webflow. But when I paste and save the new (my uploaded) URL, the site still shows the original (green) wave.
The pixels, dimensions of the wave I uploaded are the same as the original.

What is the problem caused by?
Thanks in advance.