The instructions below allow for the addition of a secondary account to a Chromebook.
click on the time icon, then click the settings gear icon
click People, then click the Upper St. Clair School District issued account selection
click Add account
enter the secondary account email address, for example, [email protected]
enter the secondary account password
after the terms of use is agreed to, your secondary account is now shown in the People listing
click on the Gmail icon, then click the account icon, followed by clicking the secondary account choice
click the browser tab pertaining to the secondary account, then click the Google app selector and choose the desired app