Selecting different HDMI inputs on the USB output port

I have an ATEM Mini Extreme and have the USB ouput connected to a computer running Zoom enabling the ATEM output to be shown in a Zoom meeting.

I know I can select different HDMI inputs to be output over the USB port using the control software on a computer but I can't see how to do it directly on the ATEM itself.

Is this possible and, if so, where is it done?

Thanks, Graham

The USB webcam output always shows you program output (basically whichever source is RED on the ATEM control surface). If you are in CUT BUS mode, then you can switch pressing of any source button (1-8 and MP1-MP2, SSRC and BLACK buttons). If you are in Program Preview mode, you can select any source, but it turns GREEN, meaning it is in PREVIEW (this way you can check it in the PREVIEW window before you switch), and you can swap it to exchange the current (RED) source to the selected (GREEN) source by pressing the CUT or the AUTO button. CUT means direct cut, the AUTO does the selected transition (mix by default).

Thank you