At 5:37 there's an oddity
Even with the "live unwrap" enabled I still need to have my mesh selected for the UV map to show up, it makes the lesson slightly incoherent to follow.
Image 1 https://i.imgur.com/2Fbihd5.png
Image 2 https://i.imgur.com/A5Tvy4D.png
Note that live unwrap is enabled.in both pictures