I have gone through the lab Write a Learning Lab Course in guided mode and I am currently working with issue #5 - Publish your course (https://github.com/bampakoa/lab-starter/issues/5).
In the section that describes how to Create the draft coursethe step 7 indicates that in order to take the draft course, I should navigate to https://lab.github.com/YOUR-ORGANIZATION/lab-starter which in my case is https://lab.github.com/bampakoa/lab-starter. When I try to access this link, I get 404: Page could not be found error.