Yes, sorry Sam. I should have warned you that you need to have the nodejs question type installed first. To do that, just do a question-bank import of the Moodle XML file db/uoc_prototypes.xml (you'll need to be a Moodle administrator to do that).
I've just moved that question type to the built-in prototypes file, so it will be standard from now on (next time I push).
Richard