Drugs.com has a list of the countries it’s available in, and under what names: https://www.drugs.com/international/ambroxol.html
Unfortunately, the US is not on that list. It might be possible to have it shipped here, but I don’t know enough about customs laws to be sure.
Wiki has an interesting writeup on it as well:
“It is the active ingredient of Muciclar, Mucosolvan, Mucobrox, Mucol, Lasolvan, Mucoangin, Surbronc, Ambolar, and Lysopain.”
We just need someone to run across the border and grab us some Ambroxol!