No longer able to set background images in css with nextjs 13?

I cant locate the image inside the public folder using background-image property with css. I am importing the css file in _app.js and using latest version of next I need to use the background image instead of next/image because it is a sprite image from https://www.freakflagsprite.com/ with a row of flags.

Freak Flags

Freak Flags

The most efficient and beautiful CSS flag sprite for displaying the worlds flags. Freak Flags are specially designed to look great on high resolution displays while delivering the smallest file sizes.