[Help please?] How do you access sprites?

This was taken from a tutorial but I am confused how he got the sprites. Where do I go? Thank you. :)

Just hit the green SmileTool button below the keyboard then hit paint in the top right.

Thank you so much! :)

No prob dude, oh and don't worry you can erase/modify those all you want, it won't mess anything up.

Thank you! I was worried there haha. :)

ive accessed them, but for some reason it wont let me use them, it says “illegal command”