Markers for manmade virus sounds like something you can opt out of if you don’t want to follow conventions. The best article I saw about whether it was human made or not stated that the virus has several mutations that made it better accommodated to humans, each of those could appear naturally, all of them appearing naturally is also possible but less likely.

Also no, it’s not like you could read a fine print ‘Made in China’ on a virus, unfortunately. Even if there are traces, those traces are much less definitive than what we can get in normal scale world