Many fonts provide automatic character variations based on the language hint, particularly Cyrillic and CJK languages. This is made possible through the OpenType Localized Form locl feature.

This only works if the typesetting environment allows the user to declare the content language. Most professional typesetting software provides this feature, and it works on the web through the lang attribute.

Figma currently lacks this capability and there’s no workaround.

This is the intended design of Unicode, and OpenType expects applications to support this, and most new fonts tend to provide monolithic variable font files instead of separated by languages, and most font vendors have restrictive licenses that prevent users from hacking around the font file, so the only sensible solution is for Figma to support it.

This was noted before.