NOTE: This article only applies if you have been assigned a full CoPilot license. Since this would incur an additional cost to the college, access is limited, a business justification MUST be provided and supervisory approval is REQUIRED.
The CoPilot icon shows in the ribbon for desktop apps only if you have updated to the latest (subscription-based) versions, classic office apps (perpetual licensed versions such as Office 2019) will not show the icon. You can still use CoPilot to draft new docs, presentations or analyze spreadsheets, you would just launch it from the taskbar.
SOLUTION:
OPTION 1: Use the web version of the office apps, you will see the icon in the ribbon.
OPTION 2: (User Services assistance required) Uninstall the perpetual licensed office suite, then download and install Microsoft 365 Office