If you want to prove that an organic compound has come from a living system you look for carbon isotope enrichment or depletion - more C12 and less C13 than found in the environment.
Not sure if that's still the current thinking, or if it ever was, but I found it interesting when I ran across it.
Of course it’s all too easy for a layman such as myself to read too deeply into things and draw unfounded conclusions about the origins of life. And if I recall, the rock is newer than the oldest known fossils, so I’ll keep a little distance on that conclusion for now
But it was pleasant to read about the earliest known fossils, so that’ll be my current takeaway on this
