To rotate a section background image, you can do these.
#1. First, find Section ID.
In my example, it is: section[data-section-id=”671f05f32e0bb94ca50140c8″]
#2. Next, use this code to Custom CSS box.
section[data-section-id="671f05f32e0bb94ca50140c8"] { transform: rotate(30deg); }
#3. Result