How to write js extern module.exports= function?

how to write js extern only have function ?

function create()
{

}

module.exports = create

only I know is exports.create = create; instead of module.exports = create

code from create

Use @:selfCall:

@:jsRequire("libp2p-relay-server")
extern class Libp2pRelayServer {
  @:selfCall
  static function create(/* options */): Promise<Libp2p>;
}

// Usage: Libp2pRelayServer.create(/* options */);