Remote worker - Do i owe local tax?

I live in PA and my company is in NJ. I work remotely from PA.

Now, my company hasnt taken out local taxes so i assumed I owed it to Berkheimer who collects it.

So i think i was told to use box 5 on my W2 but then Berkeheimer told me to use box 16.  Box 16 is usually the same as box 18.  So is that what i should be using? Box 16?