Browse As A Guest; Sign In To Your Google Account - Acer ChromeBox CXI3 User Manual

Browse as a guest

You can also use the Chromebox without a Google Account by
selecting Guest mode.

Sign in to your Google Account

If you already have a Google Account, enter your username and
password in the sign-in box that appears and click the Next button.
Important
Sign in with your primary Google Account. This account will be set as
the owner and is the only account that will be able to change certain
Chrome settings.
Getting started - 5