Sorry, it was vegan gas, not organic. They stopped labelling it that way, obviously, after being thoroughly ridiculed. It’s difficult to find references to it now, but some articles from that time (2020-2022 I think) remain, e.g. https://www.listennotes.com/podcasts/decouple/greenpeace-sel...
There might be some traces of it in the Internet archive.
I get why people laught at it but let’s not forget anaerobic digestion reactors do produce methane from manure and last centuries oleoindustrie was using tons of cetacean fat, so vegan gaz is not litterally meaningless.
I can't find anything about "organic" gas, maybe your auto translate did a wrong thing?!