A script that shows if there are updates for dnf-based distributions like Fedora.
You have to add the dnf command to the /etc/sudoers NOPASSWD of your user:
user ALL=(ALL) NOPASSWD: /usr/bin/dnf updateinfo -q --list
[module/updates-dnf]
type = custom/script
exec = ~/polybar-scripts/updates-dnf.sh
interval = 600