The 2nd-generation Amazon Fire TV Stick has USB OTG support enabled by default from the factory. This allows you to use a USB OTG cable to connect USB peripherals like keyboards and ethernet adapters. If you have a 1st-generation Fire TV Stick that has been rooted, you can also enable USB OTG support, which I’ve covered here and here. The issue is that OTG support on the older Fire TV Stick gets disabled again every time the device is restarted. This guide shows you how to configure a Fire TV Stick 1 to have OTG automatically enabled by default on boot as it powers on, so you don’t need to do it manually every time.

This guide is based on tgellen’s great guide for enabling OTG on a Fire TV Stick 1 on boot. The specific USB OTG cable that I know works with the Fire TV Stick is this one, but most others should work as well. The specific USB ethernet adapter that I know works with the Fire TV Stick 1 and 2 is this one. You can also get this Ethernet adapter which has an OTG cable built in for an all-in-one solution to add Ethernet to a Fire TV Stick.

1. Download the necessary enableotg shell script file from here. Note that this file does not have a file extension, so you may need to right-click on it and select save to download it. You may also need to remove any file extensions your PC might add.
2. Follow the first section of this guide to configure your Fire TV device to autorun shells script files on boot.
3. Follow the second section of that same guide to add the enableotg script you just downloaded as a script you want to have automatically run on boot. Be sure to replace all instances of YOUR-SHELL-SCRIPT-FILE in that guide with enableotg.