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When I look at this page: https://www.youtube.com/watch?v=aYHJY9JZNBA, I can see a chat box at the top right of the page - which can be hidden - is there "show chat" in a short wide box above the list of other videos on the right-hand-side?
Well as I mentioned before, on my YouTube app on my phone the chat box is available. However I often watch YouTube on my Xbox One and that's what I was trying to figure out because on the Xbox the chat box simply does not exist.