You can't find it here because it mostly relies on fresh made wide rice noodles. They're okay refrigerated for a day or two, but really not great frozen, and a pain to make in small quantities. If you're not living somewhere with a big enough Chinese population it's not going to be as good/popular, which means that most places won't have it.

That being said I've definitely had it from Szechuan Spice and it was pretty good.