How to insert text at cursor or right below button with button plugin

I’m using the Button plugin and would like to create a button to insert text at my cursor position or right below the button.
I’ve tried this and this works:

name Add date
type command
action Natural Language Dates: Insert the current date

I’ve tried this and it doesn’t work:

name Button
type text
action test

The first button outputs ie 2023-06-29, I would like a button to output [2023-06-29] (so to have date in between brackets.
How to make a button write text? Thanks.