Can't seem to enter BIOS settings [closed]

Have you tried:

sudo systemctl reboot --firmware-setup

--firmware-setup

When used with the reboot command, indicate to the system's firmware to boot into setup mode. Note that this is currently only supported on some EFI systems and only if the system was booted in EFI mode

Not certain of your specs on your computer, but in some cases certain bios and motherboard configs will also use the F12 key, F10 key, and possible the F2 and Delete keys together. If you look up your manufacturer's instructions on your computer they may have the key information.

If the delete key worked prior to your installation than I would still try another key just in case. However, if those keys above don't work you could manually reset your BIOS by opening your computer and resetting the BIOS with the small red button/or CMOS jumper pin - this should also be in your computer's manual. Hope this helps!