how too boot when uefi firmware setting is not showing

Have you tried repeatedly pressing F12?

What program have you used to create bootable usb?

Any kind of F keys have been tried, actually the proccess  was done under and by the supervision of a Microsoft support team remotely, and the USB to be exact was operated by the Microsoft technical person Win 10 iso, etc. The problem actually began while trying to downgrade it from Win 11 to Win 10, once it required to be restarted, it went but has never gone back, unfortunately thats just displaying dark and no logo appears. I did have this problem when it was Win 10, but at the time F4 solved the problem and I always turned the laptop on with the F4 help….,

you can try accessing the firmware settings from within Windows. To do this, go to the Start menu, click on the power button, then press and hold the Shift key while clicking on Restart. This will take you to the Windows Recovery Environment, where you can click on Troubleshoot > Advanced options > UEFI Firmware Settings to access the firmware settings.

If this doesn't work, you can try resetting the UEFI firmware to its default settings. To do this, shut down your computer, unplug it from the power source, then remove the CMOS battery from the motherboard. Leave the battery out for a few minutes, then reinsert it and power on your computer. This should reset the UEFI firmware to its default settings and allow you to access the firmware settings using the F keys.