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 am not quite sure if I understood your concern correctly. Would you like to add your OWN signature on the form? If so, then you need to create that signature as an image using some 3rd party apps, or an online web app like this one: http://signature-maker.net/. After that, you could just add it as an image to your form.
If you wish to collect signatures from your users, then you can use our widgets related to electronic signatures.
You can check the following widgets:
I personally recommend using the Adobe DC eSign signature widget. Here's a guide on how to add widgets on your forms: https://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form
Let us know if that helps.