some parts of the training ask you to comment on someone else's link, should you want to submit comments to earn credits then you use the siterubix feature

Hi Ian, howdy? Yes, you should use the "Site Comments", which is the link that you've shown in your post here to comment. By doing this, you can earn 1 credit, which you can use this credit to request others to comment on your website. It's like you help other people first, then you can ask other people to help you when you need it. The more you comment, the more credits you earned. Hope this helps. :)