The Terminal approach is valuable when the graphical user interface is not accessible—for example, when booted into macOS Recovery mode. To access Terminal in Recovery, start up from macOS Recovery, then open Terminal from the Utilities menu.
If you are buying a used MacBook Pro, always check the serial number on the Apple Check Coverage page. If the website says the serial number is invalid, or if the device shown on the screen doesn't match the physical laptop (e.g., the serial says it's a 2019 model but the laptop has an HDMI port that only 2021+ models have), you may be looking at a counterfeit or "Frankenstein" laptop made of mismatched parts. how to check serial number macbook pro