What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
There's no way or option to set the tab index order of the form fields in your form. However, you don't have to set this up since the form already sets the tab order properly by default.
Since you never mentioned which form you're currently working on, I checked the most recent form you updated and confirmed the tab order was setup properly. I cycled through all your form fields from top to bottom and the tab order was correct.
Here's how it looked like from my perspective:
If you have a form where the tab order is incorrect, give us the Form URL/ID so we can check it. Or if your form was embedded on a page/website, give us the URL where you have it embedded so we can check from there instead.