Confirmation email send upon submit?

How do I ensure a confirmation email is sent to someone who completes the form after they have submitted the form?

Hi,

You need to make sure you have setup an autoresponder in your form. Here's how to create one.
https://www.jotform.com/help/26-Setting-Up-an-Autoresponder-Email

After creating one, test your form and check if you can receive a confirmation email. Let me know if that works for you.