I can't find any good resources about how this kind of authentication scheme works where you open an app on your TV (Plex, Youtube,...) and they show you a code (optional there's also a QR code) and then you go to their website, enter their code and then your TV is logged in.
How does this work and what is it called so I can read more?
The sites they ask you to open and enter the code usually look like this:
Thanks!
I guess Google is using Oauth2 to pair clients (for example a YouTube client in a SmartTV browser) and server data.
https://developers.google.com/identity/protocols/OAuth2ForDevices
In other platforms like HbbTV 2.0 the CPA (Cross Platform Authentication) has been proposed as login for limited input devices.
https://tech.ebu.ch/groups/CPA
Other proprietary systems like Gigya uses the same approach, so you can get some info also from their documentation
