How to create a bootable installer for macOS and be certain to use a Qualifying Big Sur computer to create it.
Understand - the below will WIPE ALL DATA and there are no do overs, period.
Special Notation - this will work on Intel Based Apple Computers & should work on Apple Silicon M1 CPU
Extra Special Notation regarding the Touch ID equipped Apple Computer. About Startup Security Utility and Must Enable from Recovery Mode the ability to boot from External Drive Before Attempting
Shutdown computer and disconnect all external drive Except the newly created Bootable Installer. Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. It will present options >> Disk Utilities >> View >> View ALL attached Drives. Choose the Upper Most Drive ( not the volumes indented and list below ). The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. Once that is done >> backup out of Disk Utilities and choose install macOS. Follow the prompts and it may automatically reboot several time. Upon a final reboot - Setup Assist will present with the newer version of macOS.
