I tried accessing this link: http://gopigo3.readthedocs.io/en/latest/
And it said I don’t have permission to view the page. I got the link from here:
https://www.dexterindustries.com/GoPiGo/get-started-with-the-gopigo3-raspberry-pi-robot/3-program-your-raspberry-pi-robot/python-programming-language/
This link does work however: http://gopigo3.readthedocs.io/en/master/
Hope that helps.