I have a small script to pick at random a wallpaper every 15 minutes. I have 2 monitors and a different wallpaper for each . It still would work for more monitors.
If anybody is interested in using it :
❯ cat wallpaper3.sh
- #!/bin/bash*
- wallpapers_path=~/wallpapers*
- while true ; do*
for m in $(wlr-randr --json| jq -r '.[ ] | .name');do*hyprctl hyprpaper reload $m,"`find $wallpapers_path -type f | shuf -n 1`"*done*sleep 15m*- done;*
- exit 0*
You have to exec-once the script at hyprland start.
A sample of my desktop for 1 monitor is here :
I wiped zorin and replaced it with cachyos, zfs filesystem and Hyprland WM.
I really like it. Thanks to CachyOS team 
EDIT: You also need : wlr-randr and jq . And hyprpaper must have ipc = on in its config.