PGTonline sessions currently use the Zoom platform. Login info is provided in your registration confirmation email. You can use the link provided or enter the Meeting ID number when joining a meeting from http://www.zoom.us/join. You will need to set up a zoom account to use the Zoom platform.
Have you already set up your Zoom login? If not, you can find out more about setting up your free Zoom account here: https://conta.cc/2IU9HwF