As Mike mentioned, you can try to cast the Global.com web page from Google Chrome on a PC to your Chromecast device. Another option might be if your TV provider has their own app that supports Chromecast.
Supporting Chromecast isn't a trivial task, but I'm sure the company that Global contracts their app development out to knows how to do it, so they might add that feature when they open the app for enhancements.
I can confirm that CTV GO added Chromecast support about a year ago
Here's a useful link that lists Chromecast-compatible apps: