How to add subscript and superscript within text strings?

I would like to be able to use subscript and superscript within text strings. E.g. To include a numeric reference to a fact.

Is there a way to do this with the Richtext widget?

Looks like this pub.dev one has this feature:
https://pub.dev/packages/easy_rich_text#superscript-and-subscript

It could be done with HTML, but keen to find a way to do with the text widgets if possible please?

Thanks!