If you want to add or remove apps on Sidebar in the Microsoft Edge browser on a Windows 11/10 PC, you can use any of these two methods.

Microsoft says it removed a Copilot app that was "incorrectly" added to Windows 10 and Windows 11 systems in April due to buggy Microsoft Edge updates.

What appears to be happening here is that the Copilot app is being installed via Microsoft Edge, when folks have updated the browser to v123 (or later).