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 have replied to your other thread but you may also find this helpful.
I can see that your form's background is now transparent. However, there's a gray border as well as box shadow around the form added by the form.
First, set your default theme to "Nova Theme" on your form preference. This is to get rid of the background image found on your form that was added by Jot Theme.
Second, if you want to remove the border and the box shadow around your form. Inject this CSS codes to you form.
Or here's the easiest way to remove these. Select the theme-less icon in the Color Scheme.
Hope this helps. Thanks!