How do I turn off CNN news notifications?

CNN notifies me every time Donald Trump farts ("Breaking Wind News"), in the upper right corner of my screen. How do I stop this? I don't have a CNN app installed. Under Safari > Preferences I don't see anything about notifications. Under System Preferences > Notifications I don't see CNN. I see various apps, including Safari. I set Safari to "Safari alert style: None." I also set Chrome to "None." The CNN notifications appear even when Safari isn't running (my default browser is Chrome). The alerts seem to coincide with starting Chrome. Any other ideas how to get rid of CNN? Switch to Chromium as my default browser?