I use something like:

    echo -e "command\n with a long output,\n and it's last line" |tee /dev/tty| tail -n 1| { read -d '\n' _output ; notify-send "$_output"; telegram-send "$_output"; }

This will send the last n lines of stdout to:

- gnome-notifications

- telegram on my phone from a bot account that uses a unique notification sound

Thank you, but I don't use a notification server.

Nothing is stopping you, even if you don't run any kind of GUI session: https://github.com/Sweets/tiramisu

notify-send is for desktop(possibly gnome only?) notifications.

notify-send works by sending notifications to a notification daemon (a.k.a., a "notification server", as defined in the "Desktop Notifications Specification").

notify-send won't work for dudik since, as he said, he doesn't use a notification server.