Australian licorice is usually sold in gourmet type candy stores. Looks similar to American licorice, but is much softer and has incredibly strong flavor. Not suggested for people who have high blood pressure, which I do, so I only eat it when I have to. 2 or 3 pieces help, but I don’t know if it will affect your herd or hiatal hernia.
Best of luck to you

Australian black licorice is actually candy- warning though, be careful if you have high blood pressure. It’s so much easier to find now, thanks to the internet. In the “old day” I would purchase once a year when I visited Cape Cod which has a great candy shop that carried it.
I can’t speak to whether it affects gerd, since I don’t have it. Good luck if you decide to try