How do I import a scss npm module into Ember

How do I correctly import a non-plugin npm module into Ember?

I'm trying to use the sass version of flag-icon-css with ember-cli so that the sass is being built during deploy with the rest of ember-cli-sass, but I can't figure out how to do it in an automated fashion (e.g. without manually copying files over to public).

Using ember-auto-import seems like a good place to start but it is more tailored towards javascript imports.

I have read this documentation, but it doesn't specify something more complicated than a single file.