Introduction
Browse to https://apps.apple.com/us/app/onedrive/id823766827?mt=12 and download the app.
Instructions
1) Open the App Store from your Dock, Applications folder, or Launchpad.
2) Search for "OneDrive" or go to https://apps.apple.com/us/app/onedrive/id823766827?mt=12.
3) Next to the result for OneDrive, click the GET button.
4) Click INSTALL.
5) Authenticate using Touch ID.
Alternatively, you may verify your credentials using your Apple Account and password.
Outcome
The OneDrive app has been installed. You may access it from your Applications folder, Launchpad, or in the top right-hand corner of your Mac's menu bar.
At this point, you can follow the steps to set up your TTU account in the OneDrive app.