2FA website support

Hello, 

So i can see that i can add my accounts that uses 2fa on the mobile app, and it is working fine. The issue is I do not see that i can access that info on the web interface or even the Google extension. So lets say i am away from my phone but i am on my computer and i wanna login to an account that uses 2fa i can see the code on the web interface or extension, why is that?