Is it necessary to install additional software to use the Signature field in Vtiger? In which modules is the Signature field available? How do I add a Signature field to a module? Can I make the Signature field mandatory? In what form will the Signature be saved in the Vtiger CRM? How do I view a captured signature? Can I edit a signature after it has been saved? Is it possible to export signatures from Vtiger? Can I upload an image file as a signature? What are the limitations of the signature field in Vtiger? Is the Signature field supported in the Documents module? What is the Vtiger Signature field? How do I capture a signature using the Signature field?