Expand / Show more Block (Custom)

Hello
I really like this plugin.

I´m using an Expand / Show more Block but I would like to custom the “internal” call to action.

I would like to include a button instead of a plain text to show in the “Show More” section

In this case the message would look more like a “call to action” and not like a simple plain text.

Any idea how I can do this?

Mushisimas thank you and greetings from Spain.