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.
According to my checks on your page, it seems that you have already embedded your form with iFrame embed code; but as it is seen from the below, you don't need to take the whole structure of embed code, the content between <iframe>...</iframe> tags is enough to embed your form. (Following code is just an example, don't embed that one.)
Also, you can check the following guide to make sure that you have followed the correct steps while embedding your form.
I hope this will work for you. Please, try this one and let us know the results.