how to put square brackets and superscript?

Wrote

how to put square brackets and superscript ?

As text ... NO problem enriched of + any color

Type in text region [Na⁺], copy paste it. (you can copy from here)
Or type in a external text editor (notepad for example), copy paste it.
There is a Ctrl+Shift+K option.
You can input spaces, commas, dots, etc with it.
But it doesn't work for brackets.

Most of superscripts doesn't work.
It has limitations due to Courier New Font.
Some can be copy pasted from font managers.
It can be most needed feature right now.

Regards