Click the flag, then use arrow keys, or wasd, be sure to look at the top-right of the project when using arrow keys, or wasd. It looks like Scratch can only detect two arrow keys at a time. And it looks like Scratch can only detect 3 letter keys at the time, but idk. Also, the project wants you to use the arrow keys. Watch out for any flashing lights, especially if you are just massing the keyboard buttons.
