ULX - Play sound doesnt work

Okay, so there is an option to play sound (Look at image below), but what is the directory to play sound? I tried many but they dont work
http://puu.sh/1uf6g
This comes up in console if it wont work…
http://puu.sh/1uf6v

It says pretty clear what the issue is. The path to the sound is incorrect.

No shit…
What I need is to know the CORRECT path to play sound.

<name of folder>/<name of sound file>.<type of sound file>

EXAMPLE: siege/leeroy.wav