How do send a receipt of the submissions to the users?

How do I send a receipt with a form 

You may set up an autoresponse email in your Form to send a receipt of the submissions.

Guide: https://www.jotform.com/help/26-Setting-up-an-Autoresponder-Email

You may also attach the PDF report in the email.

Guide: https://www.jotform.com/help/503-How-to-include-submissions-as-PDF-attachment-in-the-email-notifications

Let us know if you have further questions.

Thanks.