systemreset --factoryreset

When the factory reset process is complete, the initial setup screen will appear as if you’ve just taken it out of the box.

If you’re planning to sell your laptop, performing a factory reset isn’t the only step you need to be aware of. You’ll also want to back up your data, reinstall the operating system, and more—and this applies to more than just your computer. Here’s how to prepare a computer, tablet, or phone before selling it.

https://www.howtogeek.com/171980/how-to-prepare-a-computer-tablet-or-phone-before-selling-it/