Hi everyone! I need to show a confirm dialog before a transition. We have a custom button on Step A, and after click the flow goes to Step B. I need a confirmation before going to B. Is it possible? Do I need to build an intermediate step?

You might need another intermediary state when the button is clicked to show the dialog. That way you can use the initial click to transition to the intermediary state for the dialog. Then that click will transition on through to your next state.

I was trying to use the Confirm action. But it seems that it only works for the native Save button on the record.

its a little janky but you can have button A and button B. on pageInit, hide button B. click action of button A, show button B and hide button A. then button B will do your action you want.