JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Unfortunately, we do not have a pop-up of some kind after clicking the submit button.
But we do have the Preview Before Submit widget. Please do try it out, it allows your users to preview their answers first before actually submitting the form.
To add a widget on your form, you can follow this guide: https://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form
Let us know if you need further assistance on this.