[Help] Transferring specific games between 2 PS4.

I got my brother a PS4 pro recently and he recently bought the same games I have, to save our internet quota I was wondering if there is anyway to copy my game to his console without wiping his hard drive. We are on the same network.

I have read on external HDD but from my understanding i would be "moving" my games to the hard disk and will be playing it from the hard disk. And transferring it using wifi/cable or such would wipe my brothers console.