I Have Google TV on my phone trying to cast to my TV running Android. I can't seem to find the button to cast? Is not that it won't find my TV, Is just that I can't even get into that option. I'm connected to my home wifi but the option is just not there.
Typically The cast icon should be in the top right corner of any video that supports casting.
Also if you pull down from the top status bar on your phone there should be a button for screen casting. If it's not there you may have to edit your quick menu so it is visible.
Google home app
I Have Google TV on my phone trying to cast to my TV running Android.
I blame Google for the confusion.
What TV is it? I think all TVs running Android TV work as cast devices, but I'm not 100%.
Google TV is the app that you run on the TV, not the phone. You can use it on your phone or tablet if you want to watch things locally as if it's a small TV, though.
Casting is done directly from apps that support it. Like YouTube, Chrome, etc.
next to your profile on google tv app on your phone