You must be on the McGill network (Wi-Fi or VPN) to authenticate the app.
When prompted, enter your McGill email address.
Next, enter your McGill Username (McGill email address) again and Password.
For students, the Office 365 ProPlus apps can be used to save files to/access files stored on McGill's OneDrive for Business.
Faculty and staff will be given access to McGill's OneDrive for Business in the future. Until that time, we advise you not to create a OneDrive personal account using your McGill email address to avoid any problems once you receive McGill's OneDrive for Business account.