If the person who needs to sign this return is not at the same location or accessible to the software, you can print the signature document using the Attach PDF Signature and Supporting Docs dialog.  Once you print the document, you would need to have the person sign the physical document by sending it via e-mail or physically delivering it to them.  Once the document is signed, it would have to be scanned into a PDF, and use the same dialog below to attach it by selecting the Add Signature Document button.  Choose the PDF file, and you can then finalize the signature.