How to issue notification as root in ubuntu 18.04?

Question

ubuntu

Hello, my task is that after the sleep mode, the script from /lib/systemd/system-sleep/script is doing the work.
It is advisable to issue notifications in this case.
I've tried using zenity and notify-send
but they just don't work.
I tried su user -c "command" for notify-send.
When I try to test the script with sudo, everything works.
zenity swears at the absence of something.
I also tried DISPLAY=:0.0 comand - as recommended for cron cases, but that doesn't help either.
Tell me how to do it or give a link. Thank you.

Answer 1

su user -c "notify-send 'notification'"
still works, there was a typo