What does Response SC action do? To send back a message from a Server Connect action?

I have a condition in my Server Connect action which check the submitted info. If it meets the condition then the rest happens fine. However, in my ‘else’ section I want nothing to happen but a message be shown to the visitor to say it failed.

I’ve seen a ‘Response’ action but am not sure if that’s the right thing to use or how to use it.

Or should I do something in the ‘Catch’ section instead? If so, what?

I like the way the validator works - it allows a notification message to show to the user. I want to do much the same but as part of my ‘else’ section.

I’ve tried to find info here before posting this but been unable to.