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.
I opened your form and I can see that it is already mobile responsive. This means that the form will adjust automatically depending on the screen size. It will be responsive even if you rotate your device in portrait or landscape mode. We actually have a guide on How-to-make-forms-mobile-responsive.
If I understand you correctly, you would like to prevent the screen rotation of the device? If that is the case, then you need to configure that in your device settings and not in the form.
Hope that helps. Thank you.