An email signature is a block of text automatically added to the end of an email message.
It generally includes the sender's:
Name and surname,
Title and company that they are working at,
Call-to-action landing social media channels or website
Personal information (but not in abundance).
Click Settings from the top right.
You will see a "Signature" section. Click it.
Add your signature text to the box (you can also format your email signature by adding an image or by changing the text type),
Click on "Save Changes" located at the bottom of the page.