Not only is it a purported to be a room temperature super conductor, it's a relatively high temperature superconductor, not guarantee the effect goes away if you put it under a torch.
I think the critical temperature was 400 K (127 °C).
As far as I can tell, 127°C is just the highest temperature it was tested at. The critical temperature may be higher.
The original preprint said at least 400K. They didn't find an upper limit. And for some reason, they don't seem to have the standard impulse of "hey, our potentially revolutionary material that we've been working on for 20 years seems to actually be working. Let's check what happens when we set it on fire!"
The updated preprint gives Tc of 104.8 degC. I am not a material scientist and do not know much about superconductors, but cursory glance on some of the charts in the paper suggests that the real Tc of sample they measured is somewhat lower that that, but still well above room temperature.
There are better, less destructive ways to test the transition temperature. Apparently LK-99 is hard to make in bulk, so they probably don't want to torch their sample.
or just stick it outside in a heat dome? don't you have one near you?
lol or a temperature chamber that the vast majority of labs have? heck I made a toaster oven that will go anywhere from 100F to 400F with an arduino and a $3 toaster oven from the junk store.