Makkedah

This is the name of a city. See how you translated it in Joshua 10:10. (See: rc://en/ta/man/jit/translate-names)

He completely destroyed everyone in it. He left no survivor in it

The second sentence summarizes the first sentence to emphasize that Joshua left no person or animal alive. (See: rc://en/ta/man/jit/figs-parallelism)