the video was https://www.udemy.com/course/unitycourse/learn/lecture/28701094#content
thanks you for reading
(just curious thats all)
Please go to Edit > Preferences > External Tools and click “Regenerate project files”. That often helps.
If not, please follow the instruction on this website and make sure all required extensions are installed: https://code.visualstudio.com/docs/other/unity