Chosen Solution

I just bought a MacBook Air from ebay and it has Activation Lock. How to erase the hard disk and install Mac OS Monterey?

Sadly, you can’t overcome the hardware lock or the iCloud lock unless you can get the person who had owned it give you the Firmware Password and Pin Code to properly release the iCloud lock and properly remove it from their hardware collection. Review this image and the following doc as you can encounter one or both of these

If your Mac doesn’t start up all the way Here’s a deeper view: Apple Platform Security