Video topic Part 1 HTML basics

I am in the Ultimate 3 part course on HTML and CSS in the first part in HTML Basics and in the video part but its not … working? VS code editor is saying it doesn’t recognize the encoding and I am confused if I missed a part - at the beginning Mosh mentions and I’m not sure why its being mentioned - am I supposed to download something there or - how is that relative to the section… I think he is just demonstrating a video on a webpage and it’s functionality. I don’t see that he says to do anything there specifically. All I know is that I followed what he did exactly and the editor says mp4 ( any video) is foreign encoding and the spot on the webpage is blank. Nuthin there. I can’t follow the rest of that lesson because it’s not working.

I attached the MPEG-4 preview extension but he didn’t say to do that and I have no idea how to use it lol

Can now preview it effectively - which is great but still cannot see it on the webpage… #freethevid