Earlier quoted context omitted.
And yet, at least anecdotally, it is very widely used, along with virtually every other resource that that Chinese state regards as banned.
I think they meant the US domain tiktok.com is banned. TikTok itself is not banned in CN, and its web presence there is likely available at the respective CN domain. I’m guessing it’s tiktok.cn, but I’m not checking so I take no responsibility if it’s a phishing domain.
Douyin is owned by the same company but not the same platform. It is subject to Chinese gov censorship (like all media in China), while Tiktok is not (therefore banned).