option not available as condition instruction

We would like to set up a condition as described below but don't see the option to create an 'error message' . Can you help please?

https://form.jotform.com/211753637421049

CONDITION WE WOULD LIKETO ADD:

IF (field 39) is "equal to" (field 40)

DO : show error. fields 39 and 40 can not be equal.

Do you want to show an error message using a condition?

If that is correct, you need to add a Paragraph field and the error message text. After that, you need to use that Paragraph field to show or hide using the condition.

Here's a demo form: https://form.jotform.com/211787067919065

If you want to check it and see the condition settings, you can clone it by following this guide: https://www.jotform.com/help/42-how-to-clone-an-existing-form-from-a-url