How to Turn Off Chromium Notifications?

Currently running the latest Big Sur, I've been getting chromium notification prompts on the upper-right desktop corner recently and it keeps popping up, even if I click "Don't Allow" and turn off notifications from the System Preferences. I searched the keyword "chromium" on my disk and no application called chromium showed up. My understanding is that some apps run chromium in the background, but I don't know which ones. Is there any way I can turn off this notification? Thanks.