I run grim/slurp
Looks like it does, but can you confirm if the script run fine from the terminal?
Can you send your hyprland bind config from your hyprland.conf? You'll want it set up as a global bind so no applications eat the keypresses.
Also, have you looked at wev or xev to find the name of your printscreen key?
https://wiki.hyprland.org/Configuring/Binds/#uncommon-syms--binding-with-a-keycode