It’s usually “themself” for people who use they/them! (I’ve only seen the plural version very rarely, and then it’s not usually referring to gender.) And a couple people do use “it/itself”, but it’s again super rare and kind of a reclaiming thing for the times they’ve been dehumanized, all “heck yeah i’m a b**ch!”-style. So yeah, good rule to never call someone “it” unless you know for absolute sure that that’s the right pronoun!
And thank you so much @Roby95. I’m doing my best, ha.