When you go to the Cast menu, you won't see your streaming device on the list. If you don't mind wiring in, Google now sells a USB-C to HDMI cable that supports screen mirroring for Pixel phones ...
As announced with the October Pixel (Feature) Drop last week, Google is rolling out “Hold close to cast,” or tap to cast, between Pixel Pro phones and the Pixel Tablet. Update 10/26 ...
You do not need to pay a subscription for the Google TV app, so this option won't cost extra. Here's how to set up an Apple TV Chromecast from your iPhone. Your show or movie will now play on the TV!