Hi Alena,
I’m sorry but I’m not quite sure what the goal here is exactly.
To clarify: Were you trying to simply style the forms?
If yes, forminator should have a UI for styling the form it creates. This is outside the control of the theme.
If you were trying to place a form in a post or page, you’ll have to check w/ the form’s settings if it has some sort of conditional settings.
Unfortunately, all of these are controlled by the plugin and is beyond our scope of support. It may be best to ask Forminator as they’ll be more familiar on how their plugins work. 😀