Extensions allow you to connect to hardware devices or web services.
In any project, click the More Blocks category and choose Add an Extension.
In the future, more extensions will be added to Scratch. To try out experimental extensions, visit the website scratchx.org
To use LEGO WeDo 2.0, see LEGO WeDo 2.0 Setup.
TO use LEGO WeDo 1.0 or a PicoBoard, see LEGO WeDo 1.0 or Picoboard Setup.