It doesn't; it just needs to know it was called. You make your selection once it arrives. Look up the early history of elevators and you'll see a progression f

It doesn't; it just needs to know it was called. You make your selection once it arrives. Look up the early history of elevators and you'll see a progression from fully manual in-car up/down controls (often with a dedicated human operator); various semi-automatic systems with minor improvements like automatic leveling and door control; and then operatorless systems that started with nondirectional calls: https://liftescalatorlibrary.org/paper_indexing/papers/00000073.pdf https://liftescalatorlibrary.org/paper_indexing/papers/00000...