This tutorial shows how to use the Mirror Screen feature.
INSTRUCTIONS & INFO
Ensure that the device you are connecting to has Mirror Screen enabled. Note: Amazon Fire TV, PlayStation 3, PlayStation 4, and select Samsung TVs are Mirror Screen enabled.
From any screen, swipe down from the notification bar.
Tap Settings.
Tap Display & Sounds.
Tap Display Mirroring.
Your Kindle Fire HDX will scan for available devices. Tap the desired device.
The external device will now display content from your Kindle Fire HDX in real-time. Tap Stop Mirroring to end mirroring.