If you are on a locked-down school Chromebook, the exclusive version should work even if you are behind a proxy. To test: Visit the site. If the background is black and the cursor blinks, you are ready.
Often sought for use in schools or workplaces where gaming sites are restricted, "unblocked" versions are mirror sites or alternative links that bypass network filters.
At its heart, the tool is a that outputs realistic code regardless of what keys are actually pressed on the keyboard.