Cannot access system setup

I have painted myself into a corner by setting my UEFI setup (hardware) to "fast boot".
Now I cannot access it to change it back to fix another issue.

I have set "grub customizer" to start @ EFI firmware , but it did not work - grub is still loading last menu entry ( different issue complicating current problems ) .

Any idea how to access system firmware setup AFTER the OS is running?