To begin using your cloud gaming pc, login / sign up using the mail used, for ordering your machine.

Hostmatic Now Dashboard | Connect to Cloud Gaming PC

From there, you can open the Sunshine web panel:

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:

Or from the connect page:

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.