I can't get it to work

First of all, the template I am using already has an image assigned to the background. Does that present a problem?

To start, I uploaded four images for the background slider, but I am confused about how to use the “Slide Settings.” I added the name of the four uploaded images to the end of each string, replacing slide 1, slide 2, etc. with the actual file names.

Anyway, there is no background slideshow. I did notice a strange transparent bar across the bottom of the screen. I clicked on the screen icon and got an error message for a missing script.

Help.

Thanks

https://wordpress.org/plugins/responsive-full-width-background-slider/