Form inside KM

[JMichaelTX]

@Nikao

When they select person one (radio box) more options would show up. So it is more of a dynamic form

Thanks for clarifying that requirement.
In that case, the Custom HTML Prompt is the only choice that will work.
I assume you know that this will require JavaScript in the HTML form, which the KM form can handle fine.

You may find this useful to debug the JavaScript in the KM form:
JavaScript Console in Custom HTML Prompt