You want a background image that changes form time to time. So a visitor sees different things..
Select the images and apply a CSS class.
Choose the interval. Year, month, week, day, hour, minute, second... One can also use breakpoints in order to change the picture style..
Do the settings
Make some content with the CSS class.
Looking at the page.
Looking at the same page a minute later.
This is not a slideshow..The background will not change while looking at the page.When visiting the page or refreshing, then the background will be changed if the time interval allows it.
If you don't want to use the rotation, just apply one image. An easy way to set a background.. Use an image that allows you to read the text...