I use script to load certain files in my game. I have an automated telephone voice system that will play sound clips together to form a sentence. Here's a snippet of code to show what I'm doing...
if ResourceLoader.exists("res://Sounds/Mom/YouHaveReached.wav") && ResourceLoader.exists("res://Sounds/Mom/" + names[1] + ".wav") && ResourceLoader.exists("res://Sounds/Mom/" + names[0] + ".wav") && ResourceLoader.exists("res://Sounds/Mom/" + names[2] + ".wav"):
var ring = get_node(StreamRing)
var momvoicemail = load("res://Sounds/Mom/YouHaveReached.wav")
var formerly = load("res://Sounds/Mom/Formerly.wav")
var firstnamesound = load("res://Sounds/Mom/" + names[0] + ".wav")
var lastnamesound = load("res://Sounds/Mom/" + names[1] + ".wav")
var maidennamesound = load("res://Sounds/Mom/" + names[2] + ".wav")
It works fine in Windows exports, but I think since the file system gets changed in the HTML5 export, this doesn't work. I think it's an issue with using variables to designate the file name instead of a constant path. What would be a better way of referencing/loading a certain sound with code and variables to customize the output? I hope I was clear enough explaining this. Let me know if you need more detail.