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.
If you mean to add a signature field to your form, you may have a look our signature widgets.
You need to search those on " More Fields" then just drag and drop to the form the one you would like to add.
If this is not your concern or if you need any further assistance by our side, please let us know. We would be glad to help you.