If the sensor works, enjoy the nostalgia. But for daily driving, disable it in BIOS to avoid driver conflicts and stick with a strong password or a modern USB security key.
The Broadcom USH (Unified Security Hub) w/Swipe Sensor is the fingerprint reader hardware found on the Dell Latitude E6420. Back when this laptop was released (circa 2011), biometric security was the cutting-edge feature for business machines. However, looking at it through a modern lens, the hardware and software ecosystem surrounding it leaves much to be desired. broadcom ush w swipe sensor e6420
Unless you have a specific corporate mandate requiring biometric login, skip setting this up. Stick to a strong password or a modern USB fingerprint reader if biometrics are a must. If the sensor works, enjoy the nostalgia