Notification Counter

Extension for Gnome 3.36 (and up). For lower versions, please check out v1.

Install

Copy or symlink NotificationCounter@coolllsk directory to ~/.local/share/gnome-shell/extensions.
Enable extension using Tweak Tool or

gnome-extensions enable NotificationCounter@coolllsk
# or
gnome-shell-extension-tool -e NotificationCounter@coolllsk