Pre-populate with variable/custom fields

Hello! This wasn't my question, but I believe I know what the original poster meant (and have a similar question).

According to Jotform's original example, we need to input something like this into the URL in order to prepopulate the form: fullName[first]=John&fullName[last]=Doe

This is a great and very valuable feature! But it only works if we already know the user's name. Instead, what I think would be more useful is to use variables/custom fields. We see this pretty often in email products like MailChimp or SendGrid; instead of having to send emails one at a time, users will instead use a {name} variable, and the variable will be replaced with each recipient's name. In other words, "Hello {name}" will turn into "Hello Sarah," or "Hello Luis", depending on who the email is sent to.

What I think would be useful (if it doesn't already exist) is to add the same functionality to the pre-population widget. That way, we wouldn't need to create a custom URL for each recipient--and if the recipient ever updates their information (for example, if their last name or email changes), the value of the variable will also update.

We could instead send something like this:
fullName[first]={variable1}&fullName[last]={variable2}

It may be that this functionality already exists and we just haven't located it yet! But any response would be appreciated :)

Hello,

We do have different prefill options that you can use to prefill a form. You can check the help page below to know more about Jotform Prefill and the prefill options that we offer.

What Is Jotform Prefill and How Does It Work?

Let us know if you have any questions.

Thank you for both of you, providing information about prefilled field in Post submission form.
I will look upon the information for detail.

However, currently I have resolved my issue in this case by copying the iFrame fully detail coding to become one with my main html page coding, instead of residing at JotForm web hosting online.
By doing it I can manipulate and transfer back and fort using JavaScript coding between main page and its iFrame page without any issue, i.e., because it treated as residing in the same webhosting facility even in the same web page.

The solution link, might be better for general case amongst different domain name.

Best regards,

Frans Suwardi.