No. Firestick and FireTV are not currently supported. While not officially supported there are numerous casting apps available for Fire TV devices that would allow you to cast your screen to your Fire TV device from any Google Chrome browser. The fight will be live streamed only on roughnrowdybrawl.com.
Alternatively some customers have had luck using the built-in Silk browser for Fire TV or downloading Firefox for Firestick TV. For more information, visit Firefox.com. Make sure third party cookies are enabled as well.
Note: For the full list of available devices, visit How to watch Rough and Rowdy?