How to access BIOS on late iMac Without UEFI

I have an IMac, late 2012 27” And I’m trying to boot into the bios from windows. I don’t have UEFI and i have tried all of the keys (ESC,F10,F11,F12,) and F1/F2 sent me into startup settings.

I still don’t know how to get into the BIOS

Thanks

[Re-Titled by Moderator]