Why are Cyrillic characters not displayed when inserting a font using @font-face?

Question

Fonts

There is a test page stub for the site.
It uses the Gill Sans MT font, but the problem is that the font has Cyrillic characters, and on the site they are replaced with a standard font.
I have been looking for a reason for a long time. Tried to insert ttf and otf.
All the materials that I found:
toster.ru/q/19532 But I never found an answer
Converted to otf using onlinefontconverter.com/font?id=p1
toster.ru/q/37839 Here they advised me to edit the font settings, but where to edit them? with what programs? nothing is clear, even in a full article on the subject.
habrahabr.ru/post/166291An article about fonts, in which there is a screenshot with font settings, but it is not clear where this screenshot came from, where it was made, and so on.
I don't know what to do, what could be the problem. From the link (above) you can make sure that only Latin characters work, I specifically inserted "TEST" to make sure.

Answer 1

In that Gill Sans MT that was installed, I do not have Cyrillic. I installed yours from the site - it's not there either.
Maybe the wrong files were uploaded? There is a separate Gill Sans Cyrillic - www.fonts.com/font/monotype/gill-sans/cyrillic