I decided to Google “who first invented being non-binary”.
The first person to come up is one Kye Rowan : “inventor of the non-binary pride flag”…

2014. Oh there’s a surprise – circa peak-Twitter shrieking years where anyone who told these people, or enlightened others, that they were spewing utter fucking nonsense was instantly rounded upon as a “bigot” and “dangerous”.
So case closed, yes…?
Oh not quite, apparently!! If you can bear to abuse your eyeballs by reading that not-at-all-remotely biased article, surrounded as it is by “SOCIAL JUSTICE” at the top, you will find that the writer, Meg, is a “creative”….umm…….yeah that isn’t actually a job title, deary, but then again, “gender non-binary” is total fictitious bollocks so hey – what’s it matter! You go ahead and be whatever pays the bills, eh!
Her bio looks like something a 4 year old with learning difficulties wrote:

But no no, no she isn’t writing English like a 4 year old, no, it is YOU with the problem, got it….?
She then goes on to list various bits of ‘evidence’ that noooo, the fictitious “non-binary” term was NOT invented on Twitter (that’s just a stunning coincidence that it didn’t exist, anywhere, before Twitter was around, don’t ya know , bigot). She refers to some woman depicted wearing a man’s suit of armour, and also blethers vaguely on about how some historical figures were sometimes depicted as having male characteristics, and sometimes as having female characteristics.
Err….yeah…..that’s as solid as her ‘evidence’ that it’s definitely not a Twitter invention gets. The rest of it amounts to whining as childish as her sentence construction in her bio, about “why can’t the patriarchy just accept it?!!”. This is the equivalent of saying “look I SAID it’s a thing, so it’s a thing, got it?!!”. Oh the height of maturity, madam.