There are links buried in the YT comments. The strip itself seems like a pretty standard WS2811 RGB strip. The diffuser is interesting. As he says in the video though, it probably wouldn't work without the steel plate on the side providing structural support as you need to leave the walls very thin to allow it to fit within 3/4" material.
Ledstrip 24 volt
https://amzn.eu/d/6Oji0fxDiffuser
https://shorturl.at/ktr2u