Type in a project ID (the numbers in a project url, i.e. 236462678). You can only use Scratch Team projects. This is because someone could potentially upload something inappropriate, and while that would probably be dealt with by ST, if it is used in the project, it's technically still inappropriate graphics being sent through my project, and I don't want to risk that.
my raspberry pi is slow I'm sharing this here, because my new account doesn't have Scratcher.