@VICTORHUGOBRAZI
Your screen shots show which devices you have in the Google Home app, and which devices are linked to Google Assistant. But that does NOT mean that everything works on every device. The Google Nest Help page I linked to above says:
"You can tell Google Assistant to play your Nest camera’s live video on a screen. To be compatible, the screen must be one of the following:
A Google Nest display
A display with a Chromecast device attached to it
A display that has Chromecast built-in"
I'm just another Google Nest customer, so I don't know WHY this limitation exists.
If I go to the Google Assistant app on my iPhone XR and say "Hey Google, show the Front Door", it doesn't do anything until (since we have more than one Nest Hub) I say WHICH Nest Hub to stream it on. So if I say "Hey Google, show the Front Door on the Kitchen Hub", it will stream our Front Doorbell on our Kitchen Nest Hub.
Your screen shot says you have a "Tablet Google". Is that a Nest Hub? Perhaps you can stream to that.
If I had to GUESS, I would say that since we can already stream our cameras and doorbells in the Google Home app or Google Nest app (depending on the camera or doorbell) on our phones, Google Nest probably saw no reason to duplicate this streaming functionality in the Google Assistant app.
