Overview
Users with a primary account are covered under the Microsoft Campus Agreement which includes Office 365 for home-use. You can access this software through the Microsoft 365 portal. You'll sign in with your Pitt email address, then once on the Welcome page click the Apps tab on the left hand panel > Select the pull down button Install apps from the right hand side > Select Microsoft 365 apps:
Detailed instructions are available for Accessing Office 365.
Note that home-use access of this software expires if you leave the University.