shutdown /r /fw /t 0

The command requires admin. Start your terminal as administrator on Windows, or use sudo if you enabled it.

Add permanent alias

To add a permanent alias to Powershell that the command bios reboots into bios, run

notepad $PROFILE

Then in the notepad window that opened, add this

function bios {
    sudo shutdown /r /fw /t 0
}

This version requires sudo. If you don’t want to enable it, remove the sudo from the command, like so

function bios {
    shutdown /r /fw /t 0
}

but then you’ll have to open powershell/terminal as administrator every time to use it.

Replace bios with any command you want (with no spaces) to set your own alias.