How can I include the submission data within the iFrame Embed widget to the main form?

I am using two conditionally displayed iframes to offer our registrants the ability to either pay with paypal or by check. When the registrant selects "Submit", the only information that is submitted to us is what is in the iframe.  Additionally, no autoresponder email can be sent because the registrant's email address isn't part of the iframe. I need the rest of the registration data AND what is in the submitted iframe.  How can we do this?

What you're describing is a normal behavior since you have placed your Paypal payment field on a separate form. The only data that will be gathered once the Submit button is clicked inside the iframe will be the same data within the embedded iframe alone.

To get around this, it's better to have your Paypal payment field included within your main form https://www.jotform.com/71201004250130 instead of having it isolated on a separate form. This way, once the form is submitted, all the data from Page 1 up to Page 4 will be included, along with the payment field details.

Complete guide: How-to-Set-up-PayPal-Along-with-Other-Payment-Options

In our guide above, you'd notice that the Paypal Field is only conditionally shown depending on the user selection (whether they choose PayPal or Check), and the payment field is within the main form.