This guide will show you how to add an email confirmation field so that the form user must enter their email address twice and they must match.
Add two Email elements to your form, if you haven’t done so already. One for the email address and one for the confirm email address.
Add the following code to the theme functions.php file (or create a plugin for it.)
You can hide the submitted value for your email confirm element, because it’s just a duplicate. To do that, go to the settings for the confirm email element, and on the Data tab turn off the options Show in email and Save to database.