Use the original Samsung Type-C cable. Third-party cables often only support charging, not data transfer.
: Samsung Android USB Driver from Developer Portal samsung galaxy a12 exynos 850 drivers download link
The Samsung Galaxy A12 originally launched with a MediaTek Helio P35 processor, but Samsung later released an upgraded variant powered by the (often designated as the SM-A127F). Use the original Samsung Type-C cable
How to Connect the Galaxy A12 for Firmware Flashing (Odin Mode) samsung galaxy a12 exynos 850 drivers download link
File Name: SAMSUNG_USB_Driver_for_Mobile_Phones.exe