For reference for other people, it's the green flag button near the upper right hand corner. There's also a tutorial that runs if you go to https://scratch.mit.

For reference for other people, it's the green flag button near the upper right hand corner. There's also a tutorial that runs if you go to https://scratch.mit.edu/projects/editor/?tutorial=getStarted https://scratch.mit.edu/projects/editor/?tutorial=getStarted that shows it.