How to enter bios on macbook with ubuntu?

Question

linux

For some interesting reasons, I had to install Linux Ubuntu 16.04 LTS on my MacBook Air A1237 ...
Well, it was not a problem to install it)
But how I found a more suitable distribution kit naturally wanted to install it ...
Created an image via UltraISO on Windows
Connected a USB flash drive ... And in the old fashioned way I tried to hold down Alt + Power (switching on)
But it wasn’t there! My flash drive was not on the list ... or rather, the list was completely empty!
PS I reinstalled because of problems with wi-fi but it didn’t help (((on poppy it said “no hardware”, but on Linux it just doesn’t turn on; the image is not a 100% curve; everything is fine with the flash drive because I just bought it.
Of course I I don’t hope for anything anymore, but still I ask the rummaging to help)

Answer 1

Created an image via UltraISO on Windows

Here is the problem.

Answer 2

The flash drive must contain a UEFI partition, with the OS kernel in a format understood by the UEFI bootloader.
(or with an intermediate bootloader in UEFI format, such as GRUB, which will already load the OS further)