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.
I'm not sure how you're embedding your form, but here are two guides that will help you with that:
If this still does not help, please provide us the Facebook page where the form is embedded on, we will be glad to check it and find if there is something that is not allowing to submit the form.