There is no magic "Exynos 850 chipset driver" separate from Samsung’s standard package. The safest, fastest, and most reliable is the official Samsung USB Driver from developer.samsung.com .
To install the Samsung Galaxy A12 Exynos 850 drivers, follow these steps: samsung galaxy a12 exynos 850 drivers download link
Technically, Windows will install a generic MTP driver automatically. However, that driver often fails with "The device has stopped responding." The official Samsung driver resolves this. There is no magic "Exynos 850 chipset driver"