Show notification on electron app that serves react app

I'm trying to serve real react app on electron app. It doesn't mean I'm developing electron app with react. I've created a react app and injected it into electron app. (Like slack, it will serve as a web application and desktop application.) But I'm confused that send desktop notifications.

Now the main question is: How can I get the application type. I mean, is user using my app on web or on desktop. How can I get this?

Thank you :)