Why image is not applied when I try to apply it in CSS?

Question

I write background-image:url(https://www.pexels.com/photo/clouds-landscape-niagara-falls-river-149472/; but it doesn't work. Why?

Answer 1

It should be like this example
background-image:url("http://example.com/img.jpg");

Answer 2

your url seems to point to nothing... try to put a valid image file url ^^