If you have access to a printer and scanner, you can sign a document digitally by using an application that supports this. There are many options out there, such as Adobe Acrobat. There are also some online free alternatives.
One of these is Eversign: https://onlinesignature.com/
To sign your document upload it to their site and input your email address. The site then will send you a signature request to your email. You may sign and save the document then.
