Microphone for Ok Google actions

[Pushpike]

I have not tried it on my Pine64, but on my other devices running Android 7.1.2, I use my older webcam with builtin mic.  It works great, it sits on top of my 65" Samsung TV.  It can do Skype and use Google assistant.  No more saying "hey Google", just tell it what you want.  I control my lighting and control my apps right from my TV with my voice with the builtin mic on the webcam.  

I am using my Logitech C310 webcam.

Thank you for your advice.
1. How can you do it without "OK GOOGLE" or "HEY GOOGLE"?
2. When I activate google assistant saying hey google, my screen turns sideways (portrait mode). How can I keep the screen in landscape mode.?