2017 Macbook Pro Erase

If you are selling or recycling the laptop, then perform the steps in this Apple article first (last step is performing a clean install of macOS):

What to do before you sell, give away, or trade in your Mac - Apple Support

Read the full article. There are two approaches: How to reinstall macOS - Apple Support

You seem to need the "Other ..... "

I had to reboot to install 12.3.1 ....

Another good article: https://www.howtogeek.com/186860/how-to-reinstall-os-x-on-your-mac-wipe-your-drive-and-create-usb-installation-media/