Open a support ticket with Atlassian.
If standard Chinese characters cannot be displayed, then it's a problem with the Confluence Cloud platform and Atlassian need to update their internationalisation files to support Chinese users.
If you are hoping to use non-standard characters with non-standard fonts, you are likely out of luck, because it is a non-trivial task to add custom fonts to Confluence Cloud. It is however very straightforward on Confluence Server.
You will need to go to the Marketplace and look for a plugin. i am afraid since you are a Cloud user there won't be that many add-ons. Click on the link below:
All the best,
Hi All! We’re excited to share the launch of an announcement banner that lets Jira site administrators communicate directly to their users across their Jira Cloud instance. ...
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