Create a Gmail signature

https://support.google.com/mail/answer/8395?co=GENIE.Platform%3DDesktop&hl=en

An email signature is text, like your contact information or a favorite quote, that’s automatically added at the end of Gmail messages as a footer.

Add or change a signature

You can put up to 10,000 characters in your signature.

1. Open Gmail.

2. In the top right, click Settings Settings.

3. In the “Signature” section, add your signature text in the box. If you want, you can format your message by adding an image or changing the text style.

4. At the bottom of the page, click Save Changes.