Sync with China-specific server

[ICHx]

According to the customer service, there is only a small subset of obfuscated server working in China. However, I cannot figure it out how to choose only from the obfuscated server group(not exist in "nordnm l --categories"

and/or to specify a server configuration to sync.

For example, I want to import Sg999 by "nordnm s", how can I do that?

Many thanks