This is from the Chromecast site:
- Open the Chrome browser on your laptop.
Add the Google Cast extension from the Chrome Web Store.
Visit any website in Chrome.
Click the Cast button in the Chrome browser and select your Chromecast.
If this is what you did, maybe the Global web site isn't compatible for some reason. I don't have a Chromecast, so I can't verify it.
Edit: I see you got it working as I was posting this.