I don’t know if you can use it to translate your own string (eg. for plugin localization)
I believe it’s more to get localized string from Ps UI if you know the /slash/separated/key part used internally. For example, to get filter menu translation, you’d use $$$/Menu/Filter (ref)
If I’m not mistaken, @Jarda mentioned something about this briefly. IIRC you can find these keys in some old CEP docs or something.
Yeah… Don’t take it for granted, because my memory isn’t that good
On a Mac, you can find the ZStrings in the file /Adobe Photoshop 2025/Locales/en_US/Support Files/tw10428_Photoshop_en_US.dat.
If you have installed PS in a language other than en_US, the local code may be different, e.g. de_DE etc.
You can open the file with a text editing app or also with Vscode.