bios - How to use external display as default

When I use my external monitor with my laptop, the external monitor begins to display when the OS starts to load, unlike the internal monitor in the laptop, which begins to display from the beginning, including the OEM Logo and bios.

It is the same when I connect the monitor to my old laptop or my friend's laptop.

It doesn't matter at first, but recently I go an embedded machine, I want to use the external monitor to setup OS, although the monitor detected signal, but do not display anything.

The embed machine is functional, because it worked when I use my friend's monitor.

So how to make a external monitor work as the default monitor of a computer, so it can display when booting up like desktop?

Or there are differences that some monitors can and some can't?