First you need to add the sound to the scene. In the main UI, select "scene audio" and add your file.
Next you will need something to play the sound. Add "audiosource" under the sound tab in "add atom".
Finally you will need a way to trigger the sound. There are many ways to do that but lets use a button. Add a button atom (in the triggers tab of add atom).
In the button action you will do: Receiver atom: audiosource. Receiver: Audiosource. Receiver target: play now. Select the sound.
Now when you push the button, the sound will play.
