Why are there no pinouts anywhere?

None of the documents that come with my Pi-Top 3 tell me which pins are which on the header next to the breadboard on the “Inventor’s Kit” – I can look this info up for a Raspberry Pi, but then I don’t know which corner of the header is pin #1 – nothing is labeled! Getting that wrong is a good way to make a cloud of smoke appear. I can test the pins to see which have 3.3 volts and then figure it out, but isn’t this thing designed for ten year olds? I have a feeling they’ve already destroyed their Pi-Tops.

???

That is a standard GPIO40 pinout