How can I link a new form element to my imported pdf?

The signature field on the imported pdf form did not come through with the digitalised signing option, only as a short text entry.  I can create an e-signature element but don't know how to link it back to the pdf and replace the other field.  Is this possible?

Hi,

To my understanding, you have imported a fillable PDF file to JotForm? If so, the changes that you made on the imported file will not be able to link it back to the original PDF file. Unfortunately, all the changes that you made on JotForm PDF Editor can't be linked to the original file. 

You could provide us which PDF form are you trying to create if you need further assistance.