I want to see which notification daemon is running. This is because I want to replace it, since it does not properly confirm the notification from blueman-applet.
I mention that I am running the i3 window manager.
I found out myself.
xwininfo to find out which process created the notification window.notification-daemon or xfce4-notifyd)In my case the culprit was dunst, which did not show buttons to Confirm / Deny the Bluetooth pairing.
Edit: another answer seems to be more complete (showing you the mechanism of Unity notifications).
dunst and deal with confirm/deny buttons?