Hi Craig –
As the error states, you’ll need to have the engine that you want to initialize defined in the context in which you want it to run. So, I guess the question here is what are you passing as the value of ctx?
As a side note, I’m not sure of your use case, but you might want to consider the Bootstrap API, as it’s designed for exactly what you’re mentioning. The code snippet here is a good start.
Let us know if you have any questions as you go along.