Please let me know how to download the publishsettings file for Azure China from the Web Portal
As far as I know, if you want to download the webapp's publish profile, you could directly open your wen app, then click the download the get publish profile button to download the webapp's publish profile.
Image like this:
If you want to download the subscription publishsettings, I suggest you could run below powershell command(Get-AzurePublishSettingsFile) or directly open this url from your browser, it will auto download the publishsettings file.