MacBook Air M1 Not Showing Startup Disk

Was just given a MacBook Air M1 by my elder brother. He never signed in his Apple ID as he mainly used it for movies.

The problem now is after reinstalling Big Sur by clicking on options at startup, then using disk utility to wipe the disk, the startup disk no longer shows up at boot.

I’ve repeated this thrice now and the first time I did it, it connected to the internet to ‘activate my mac’. I’ve also used an external drive to install the OS but the issue persists, after OS installation completes, the startup disk doesn’t show.