Webstorm and npmrc - none standard package location (prefix)

I'm trying to get the React Native and React app project generators working, but It seems that Webstorm is unable to find their installation location.

I have added a custom prefix in my .npmrc file that changes the prefix for my system user to ~/.npm-pkg, but it seems webstorm ignores this setting and is looking for globally installed packages in the standard location, rather than my system users specified location.