Afaik the English version of the lore has always been 'he'. The original story according to the original language though, idk.

...I'd guess the original also used masculine pronouns though, mostly because of the whole triune thing - their 'god' is actually three critters rolled into one. There's the 'father' or what most people mean by the word 'god', the 'son' or 'Jesus', and 'the holy spirit' which is basically The Force from Star Wars.

I don't recall a sex or gender ever being assigned to The Force, but even if it is canonically female, the sausage fest from the other two would still tip the scales into 'he/him' territory.

They/them is probably the most accurate even of the lore itself doesn't use it - between the three, god is gender fluid. Volatilely so if we're going with the kaleidoscopic dance in the pants that is my preferred head canon (there's nothing in that book that suggests this isn't the case, and believing based on the lack of disproof is the whole basis for their cult in the first place, so I'm rolling with it!).