How to mix in cubase and redirect to zoom for live?

I have a keyboard with Yamaha ASIO through usb and a microphone from the PC.
I added 2 audio tracks, but the second I could only connect “stereo in”;
I have a headphone connected to the keyboard, which receive the sound from the ASIO usb (in the other direction).
My motherboard is Asus ROG MAXIMUS XI HERO (WI-FI)

  1. how can I have the microphone in ?
    2 how can I / should I export the result to go into zoom, which supports only 1 interface (eg., either microphone, either ASIO) ?
    2a should I use control room ? then how to redirect control room to zoom ?

Many thanks in advance !