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.
Do you want to set a background image in your form? If that is the case you can do it through the form designer: https://www.jotform.com/form-designer/tuts/episode10/
If you want to set a image on the submit button, then select the button field, and add the image in the above option:
Let us know if you need more help.