I've installed Ubuntu 20.04 LTS with keyboard "English (UK, extended, with Win keys)".
I'm confused about where to find certain characters. For example, AltGr+1 gives superscript 1, AltGr+3 gives superscript 3, so why doesn't AltGr+2 give superscript 2? Superscript 2 (meaning squared) is much more useful than 1 or 3. Where can I find superscript 2 on this keyboard?