Yes, you need to sign your tax form to be valid.
To do that, you can use one of the available apps (Adobe Acrobat Reader, Preview) that allow you to create and insert a signature into the signature field.
You can also print, sign, and scan the document and send it over to us.
Alternatively, you can type your name in and add a separate time and date stamp next to the signature field with a short note that says, "This form has been electronically signed."
If you need any help with signing your tax form get in touch with us on firstname.lastname@example.org.