If you're mirroring your screen and landscape mode doesn't work, try casting instead.
Please follow the steps below to enable casting:
Tap on the cast icon (only long-form videos)
Select your device from Connect to a device list., e.g., AirPlay & Bluetooth devices.
Follow the next steps as they display on the screen.
NOTE:
Please make sure to enable the Local Network on your device. You will find that option under the Settings section.
If you’re trouble with casting, try casting to web: see video.