Not sure how I did this but I installed battle.net and wow launcher on an external Ssd to play on my Mac. The battle.net launcher was then moved over to my Mac internal ssd. For some reason I can launch Wow from the battle.net app on my internal without my external being connected but I can’t find the actual wow folder anywhere on my Mac, hence why I can’t install addons. Any Ideas?
In the battle.net app go into settings and then click on Game Settings. The location of the game will be shown there.
bizarrely it still says the wow install location is on the external SSD
Moving the launcher does not relocate the game itself. They are two separate programs.
I don’t know (or like) Mac’s, but with a PC, when a program is running, you can fire up task manager and it will show you the absolute filepath the program is running from.
Maybe something similar is possible with Macs?
If there is, I don’t know how 
I tried running a script for worldofwarcraft.app but it says it can’t be found in the directory