notify-send won't show up on generic X sessions, but works in a KDE session

I have Suse Tumbleweed, and sometimes I work in a KDE Plasma session on X, and in this case [notify-send](https://man.archlinux.org/man/notify-send.1.en) works as intended. Othertimes I use icewm or compiz as my window managers, and in both cases notify-send does not work as intended, that is, no popup windows is shown (but no error condition is raised). How can I have working notifications in every case? --- I understand that my question is a bit sketchy, if you have any question I'll be happy to add further info.