Resetting Macintosh HD
I bought a used 2017 Macbook Air earlier in the year. I have never been able to access the Macintosh HD as I don't know the password for when I've rebooted and it asks to enter a password for Macintosh HD. Is there any way to format or reset this so I can access the extra 66 GB of storage which I currently don't have access to.
MacBook Air 13″, macOS 11.3