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.
The form is set to be responsive. It means that it will adapt to the screen on window sizes. So you need to adjust the width of the Lightbox form.
When you embed the form using Lightbox code you can see the settings of the form. Look for this code and change the width to 769.
Hope this helps. Thank you.