This is my first time going into stock recovery on my 6P, all of my experience before was with my Nexus 5. So forgive me if this is an obvious answer.
When I go into the bootloader, then go to recovery it just shows the little android guy with "no command." If I remember correctly the Nexus 5 went straight into options of which option you wanted to sideload. From ADB or storage and so on. Without having to do anything else before getting to those options after selecting recovery, right? I could be not remembering correctly.
Anyways from this point after selecting recovery for the 6P, what do I need to do to get to the 'sideload from adb' option? I tried clicking the volume and power buttons a couple different combinations to enter into a list of options to sideload but nothing happens except boating up eventually. Also yes I tried searching and also no Heisenberg's awesome guide does not mention anything about this. Seems as if it should go straight into these options from his instructions.
EDIT: someone answered else where. It was power button with volume up tap.