To begin using your Cloud Gaming PC, open the URL sent to your e-mail by pressing this button

As outlined, you’ll get an SSL Warning, select continue to site.

Download the Moonlight client for your device

Moonlight Game Streaming: Play Your PC Games Remotely

Select Add PC

Copy your server address from the yellow bar found in your welcome mail, and paste it into Moonlight:

Select Gaming-VM, a PIN will show, go back to the Sunshine control panel, and enter the code shown.

After successful pairing, you can now access the Desktop or start Steam in Big Picture mode.