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.
If you are referring on how to pass predetermined or prepopulated fields (ex. Unique ID), you can do that by passing the Form's URL with value parameters. You could check this guide that we have here, Prepopulating fields to your JotForm via URL parameters..
This widget might also help you generate unique IDs, Unique ID widget.
Let us know if you need more information about this.