Running which version of WOW, it will write its own path in the registry, plug-in installation will automatically look for this path. So you should run the appropriate version of WOW first to change the path in the registry, and then install it.

For example, if you want to install the national version, run the national version of WOW first, and then install it, then the path will point to the national version, and the path will be correct. If you want to install the Taiwan version, you should run the Taiwan WOW first, and then install the plugin.

The same problem occurs with the WOW upgrade patch, if you don't run the appropriate version, it installs into the WOW directory where you last ran it.