how to add information on ShowOnSubPages?

How can i add information on subpages "ShowOnSubPages"? i see that if i add "ShowOnSubPages": "1", it adds a button but where do i add the text?

Hi,

This is described in the overview. If you want some element to be visible on subpage 1 only the set its "ShowOnSubPages" to 1.

If you want it visible on 1,2 and 3...set it to 1,2 and 3.
Formatting examples are given.