I have an app that uses OpenVidu. It works fine. I can use the app to call someone that is waiting for a call on a web page.
Can I do the inverse? Can the web page (the OpenVidu Inspector I guess) call an app/phone?
If you want to receive calls you have to implement some sort of notification mechanism in your web page or mobile app.
For web pages: https://developers.google.com/web/ilt/pwa/introduction-to-push-notifications
For mobile apps: Push Notifications Explained | Airship
Best regards