Not near an account right now but literally just "View Source" when signed in and search for "copilot" and it's there along some other feature-flags for the user in a JSON blob inside a script tag.

Not sure why this is downvoted, I just checked and I do see a json object inside a <script type="application/json" id="client-env"> tag, that has all kinds of copilot related keys.

I checked my profile and copilot is enabled with a "lock" icon, I cannot disable it. I have never enabled it.