Click here for all of the CGHS Action Research resources!
A link to the official tutorials on the Peergrade website is posted at the end of the page. I have made a set that is similar to the site you will access, so follow each video to use Peergrade.
https://help.peergrade.io/en/articles/683065-teacher-video-tutorials
The site has evolved and hence the official videos may appear different to your platform.