If I’m understanding you correctly: check the introduction to those challenges – there is a link to repl.it, which is the online service you’ll use to do the challenges.
Sign in to replit and you’ll use the app skeleton in the link, and gradually build it up through the challenges. To submit, you’ll need to link it at each step to the tests can be ran
You have the option of cloning the boilerplate code directly from GitHub - this allows campers to work locally, or on other platforms, and commit their project to their own git repository.
The catch to developing locally is that you still need to host a live version of the project somewhere for our tests to see.