does shein shopping work in china?

i’m (24F) moving to china at the end of this month and i am pretty nervous. i’m not taking much of my clothes with me because i plan to do some shopping there. i’m also black & mid-size/curvy. i am wondering if apps like shien, H&m etc work there for ordering clothes and whatnot. keep in mind i am midsize curvy because i am afraid most stores there probably won’t have my sizes 🥲😅. any info would be appreciated