How do I screen-cast Phone (2) to my TV?

First, set up the screen cast feature. Swipe down twice from the top of the screen to access the expanded Quick Settings. Press the pencil icon and drag the Screen Cast tile up from the hidden tiles.

To start mirroring, swipe down to open the Quick Settings and find the newly added Screen Recording tile. Tap it and select the target cast device to connected in the same local area network.