How to create shutdown sound, Ubuntu 20.04

I have these two links that say how to create and link for shutdown sound. has not worked for me yet. I have changed the file to K99 and k01.

method 1-

method 2 -

Any help is appreciated.

I am also looking for a way to execute a script at shutdown. So far, no luck.

Tried to create a script (folder creation) on /etc/init.d starting with "K99" but it wasn't executed.