On the plastic container of the kit I received it says "Browse to https://onion.io/kits to start learning and building!". But when I go to that URL, I only get a 404 error.
Posts made by Ulf Zimmermann
Maker Kit, includes fake Futaba servo S3003
So as I was looking for the pin layout for the included servo, I found that it seems this is a fake version of it.
For example see this web post:
Or this video on YouTube:
The one I received looks like the one on the right in this video. Mounting holes further out and open, plus the top matches.