When Copilot Chat is installed you will have a button as in the image. When clicking the button copilot will analyse the commit diffs and suggest a commit message.

I understand that there is a negative sentiment regarding copilot writing commit messages for the programmer. But in my humble experience I have noticed that commits are often better written and more complete than I would have written myself. Plus copilot learns from your previous commit messages and tries to match the style. This allows committing much more often which is a good thing in my opinion.