Here's the instructions from the guide:
If you are submitting this form electronically:
You must fill out the form on your computer, validate it, and save it to be able to submit it electronically. You will not be able to upload a form that has been printed and scanned, even if it has been validated.
In the signature section, type your name and select the date using the date selection tool.
When you submit your Schedule A electronically through your online account, you will complete an electronic signature when you upload the document.
At that time, you will certify that the information provided is true, complete and correct.
You do not need to print a copy of the form or sign a paper copy.
If you are submitting this form in paper format by mail:
You can fill out the form on your computer (recommended) or fill it out by hand.
If you are filling it out on the computer: In the signature section, type your name and select the date using the date selection tool. Then, print out the form and sign in writing (provide your original handwritten signature) next to your name in the signature box. If you do not sign and date the form according to these instructions, it will not be accepted and will be returned to you.
If you are filling the form out by hand: In the signature section, sign your name and complete the date legibly. If you do not sign and date the form, it will not be accepted and will be returned to you.