Help needed for my extension

Now that i have your attention, i have a query regarding my extension,
i wish to confirm something, i’m using this function in my extension, it gives me the channel id, what i want to know is that, the id i get, is it from, the streamer (someone who has my extension installed) or the viewer who is logged in?

window.Twitch.ext.onAuthorized((auth) => {

Also it would be really helpful if you could provide me with a way to get both id’s, from the streamer and the viewer, is it possible?

channelID is the channelID of the page

if a viewer has granted access the userID is is the auth payload as documented: