Technical details of the content to be distributed simultaneously

[tamon2024]

(I am not familiar with English. There may be differences in terminology.)

My position is co-host.
I recently set up a simultaneous stream to Youtube using the Zoom feature.

It worked as expected, but I could not figure out the details of what was being streamed to the Youtube side.
At least, it seems that the host's Zoom screen is not distributed as is.

We are looking for the details of how it is streamed when we perform any operation.
For example, I want to show only a group of people I specify.

It may be in the help, but I couldn't find it.
Where can I look to see what is being streamed?

Thanks for reading. Waiting for help.