Once you do so, make sure to create a class (can use Google Classroom). Then, go into the web page, select the extension and then add a question, embed a YouTube video, etc. and assign to your class. Once assigned you can go into the Dashboard and see your lesson(s) and see what lesson has been assigned (and edit/delete if needed).
You as the teacher can also hide comments on the site by selecting the circle with a line through it under the time of the comment see below).
Embedded below is a 2 minute and 38 second YouTube tutorial.