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 have inspected your form and only Terms & Conditions field is required. I also tested your form and I was not able to submit it without filling that field. Are you unable to make some other field required? If so which one?
To make your field required, inside of your Form Builder you need to select that field and Turn ON required option. You can click on required option in top tool bar menu once you select your field or you can open field properties and turn On required option.
On my cloned form I have made all fields to be required.
Here is my demo form: https://form.jotform.com/62252255818962
Feel free to clone it.
Hope this will help. Let us know if you need further assistance.