If you're curious, first try out seeing if you can make a text box with Unity's standard text mesh. STM has the same implementations as Unity's default text renderers, so if you can set TextMesh.text, you can set SuperTextMesh.text!
Also, if you're looking for a dialogue manager with localization support, I've actually recently released my own, Fleece! https://kaiclavier.itch.io/fleece
That said, I don't have that many examples set up yet for non-programmers, so my feelings won't be hurt if you go with a competitor, haha