Navigate to to Steam\steamapps\common\wallpaper_engine\projects\defaultprojects
Create a new folder 'openrgb_wallpaper' and extract the content in the zip into the folder.
Launch Wallpaper engine and apply.
or click Subscribe button on my workshop
https://steamcommunity.com/sharedfiles/filedetails/?id=2942091593
Upon applying for the first time, Wallpaper Engine will prompt you're about to open an external application as a wallpaper, check Don't ask again for this wallpaper and click Proceed. This is absolutely fine Wallpaper Engine will warn user when they launch any executable file.