this is a duplicate of my answer to the question on 26 Oct 2018, only because i wanted to make sure the subject line was very clear and to the point. once you figure this technique out, it's really easy, but it's not necessarily obvious how to do it from the video because there are no shortcut keys shown (perhaps because the Screencast Keys addon didn't exist in those dark and distant days).
at 4:25 in order to replicate the tutor, you need to hover your mouse cursor over any or all of the first three blocks of parameters (Location, Rotation &/or Scale) and press i (must be lower case it seems). Dimensions won't work, but then you would control size with Scale anyway.
it's as simple as that.
then you move the playhead to your next target frame for keying, move your object, then once again put the cursor of the parameter block you wish to key, and press i again and that would add a new key with those parameters (as you see at 4:55).
doing it this way will make a prolix or profuse bunch of key channels in the dopesheet, but as chris explains, you can easily group them later by selecting them with shift and then pressing control G. you also get to name them whatever you like.
hope this helps,
julian darley