Spacing Cyrillic

Snímek obrazovky 2022-03-07 v 12.47.48
Why can’t I write on russian keyboard when setting up spacing? I switched the keyboard to Russian, but when typing it is still written in English.

You can only type ASCII letters (i.e. glyph names) in the text field as far as I understand.

Why can’t I name glyphs in Russian? Is there any tutorial about naming glyphs?