Newbie question

I just bought a blackmagic atem television HD Pro.
I set it up and everything seems to be working (cams, multiview, update, etc). My only problem is that I have no idea how to broadcast with it in YouTube channel. I think I might know what I was doing wrong.i was using the usb 2.0 to broadcast with it. My question is, which is the video output.

The new TVS HD does not have a capture option.

USB is only for firmware updates.. You need to buy a Webpresenter, Capturecard or Hardware streamer to go to youtube.

He's right, you're looking for something to capture the program feed (program = main output) into your computer, then use Open Broadcaster Software or something similar to encode the video and stream it to YouTube.
An Intensity Shuttle (USB) or Mini Recorder (Thunderbolt 2) will do what you're looking for, and OBS is free. Overall not hard to set up, just make sure you get the frame rates right.
Magewell and other companies also make capture devices.