How to enable ADB debugging on the Amazon Fire TV or Fire TV Stick with New UI
Follow the simple steps below to enable ADB on your Fire TV device.
Note: This guide is for Fire TV OS version 126.96.36.199 and newer.
While on the home screen scroll right to Settings.
Scroll to the right then select Device.
With the Device dialog open select Developer options.
ADB Debugging is now enabled on your Fire TV or Fire TV Stick. Your Fire TV is now setup to allow side-loading .apk files.