What is the GitHub username? I am an edX user and when prompted for GitHub username for example by check50 or submit50, I don't know what credentials to input. My edX credentials do not work.
Have you done pset0 yet? Maybe you should start with that one.
In order to submit problem sets, you’ll need an account on GitHub, a popular service with which to store code and collaborate with others. If you don’t already have one, visit https://github.com/join and create an account (for free). Take care to remember your username and password! If you’d prefer not to provide GitHub with a personally identifiable username and email address (i.e., one that includes your name), you’re welcome to create an account using an anonymous username and some other email address (e.g., that you only use for GitHub). If you choose to provide a personally identifiable username or email address, material you submit for the course to GitHub and our feedback on it also will be personally identifiable by GitHub. See GitHub’s Privacy Statement.