Click the green flag. In case you don't know what I mean by id,look at this, https://www.youtube.com/watch?v=8nYMR9yB4g8 the ID is 8nYMR9yB4g8. So the ID is always after the watch?v=.
Credit to the code in my last project,which was made by @World-Languages,but this time I didn't take the code:I used 2 tabs to look at the code,so I basically edited it.