Need help for language
Isn’t the Chinese GW2 service run locally and not connected with the Anet service?
I remember reading about that Chinese system some time last year, a quick Google came up with this example thread:
https://forum-en.gw2archive.eu/forum/game/gw2/i-m-a-chinese-player/first#post4503457
If you purchased a Chinese client, you can read this article in the Knowledge Base:
https://help.guildwars2.com/entries/57504097-Guild-Wars-2-is-Now-Live-in-China-
If you want to play the version of the game that supports English, you will need to buy a NA/EU version.
Good luck.