I suggest YouTube as the best one to watch. They sometimes edit but this will be live. It will also be on Rumble and C-Span.
https://www.youtube.com/live/vqSSEZQMHSs
See Posts #222 and #223 for some links. :)
The link in post 223 goes straight to the debate, when it starts.
The one in 222 has commentary right now; not sure if this is the one for watching the debate itself.