How to insert an eSignature field in the form?

There are several options to do that. All of them are as simple as dragging the widget and configuring it if needed. Please try them and do not hesitate to ask any questions about them. http://widgets.jotform.com/search/signature

I created a sample one for you so you can quickly clone it: https://form.myjotform.com/63414365378562

aminekh got all the information you need. Please follow the instruction to add the widget. If you have any questions about it, let us know here.