something like this. The text or image under the button should be part of the form. How am I going to do that? Thanks in advance.
You can move any field below the Submit button.
I wouldn't use CSS to fake it (though that could also work) because it makes positioning too delicate IMO. Instead, literally move the fields below the button using JS, so they stay in the standard flow.
In MktoForms2 :: Fields below submit I'm moving a Rich Text field like yours -- together with, and this is very important, its entire wrapper row -- below the button. In the RT editor I made sure to give it an easy-to-find ID (Rich Text fields don't otherwise have a distinctive name).