Error Importing Images


First-time Bootstrap Studio user here.

Whenever I try to add images from my desktop, I am unable to fully utilize them in Bootstrap.

Specifically, I using the drag and drop function, the images will show up in web preview, but when I try to replace an existing image from one of the header templates <<background-image: url(xyz.jpg);>> the image shows up in the Bootstrap preview but not in web preview.

Additionally, the css is red with a line through it. Am I importing the image incorrectly? Suggestions?