Fairly sure that's how the Chromecast SDK works. That will cover a good amount of ground for you, as many modern TVs are chromecast targets. Source: about 2 years ago

But I don't believe Fire TV supports Casting (the specific Google-developed protocol that Chromecast and other devices support). Source: over 2 years ago

This might help: https://developers.google.com/cast. Source: about 3 years ago

I read somewhere that Google Ad Manager can solve my Problems. Is that true? Can someone send me a link of their documentation where they show this feature? Because I don't understand really Google Ad Manager, I saw their website https://admanager.google.com/home/ but it feels like AdSense, just for businesses who have more ad space with different interest groups and so on with better ad network Management or... Source: over 2 years ago

Thanks for that info! Yes, I filled out a form at https://admanager.google.com/home/ and that's when this Google person reached out to us. Source: about 3 years ago

You sure you just signed up at https://admanager.google.com/home/ ? Just register an Adsense account, then a free GAM account and you should be good to go. Source: about 3 years ago